Chapter XV: Lead (1)

BY FREDERICK B. HYDER

USES OF LEAD

Lead is used in the form of the metal, of alloys with other metals, and of various chemical compounds. As metal its chief uses are as pipe for water and corrosive solutions; for protective covering of electrical cables; as sheet lead for lining chambers for the manufacture of sulphuric acid and vats for chemical manufacturing processes. In smelting, lead is used as a collector of other metals, particularly of gold and silver, from which it is later separated, now most generally by the use of zinc by the Parkes process of desilverization.

Lead alloys readily with nearly all other metals in all proportions. Its alloys of industrial importance comprise type metal, bearing or babbitt metals, shot, solders, casting metals, some brasses, and the fusible alloys used for the protection of electrical apparatus and in automatic sprinklers for the protection of buildings against fire. Type metal, originally composed of 83 per cent. lead and 17 per cent. antimony, now often contains bismuth and sometimes a little copper and iron. An alloy of 9 parts lead, 2 antimony and 2 bismuth is used for stereotype plates. Less than 2 per cent. of arsenic is added to lead used to make shot to increase the hardness and sphericity of the product. Antimony also imparts the hardness essential to shrapnel, etc. Bearing metals comprise alloys of lead and antimony or these with copper, tin, and zinc. Antimony imparts to lead the property of expansion on solidification, essential to type metal and casting materials generally. Lead makes a brass that is soft and machines easily. Solder is commonly an alloy of lead and tin. The melting point varies with the proportions of these constituents and others, sometimes added for special purposes. The cheapest solder in general use is 30 per cent. tin and 70 per cent. lead. Solders seldom contain more than 50 per cent. tin. The addition of bismuth, cadmium, or mercury lowers the melting below the boiling point of water. Fuses can thus be obtained which interrupt electric circuits at any desired temperature.

The largest uses of lead compounds are as pigments. White lead or basic carbonate, 2(PbCO₃)Pb(OH)₂, is the most extensively consumed, being used alone or mixed with zinc oxide and barytes. Red lead (Pb₃O₄) is used for painting structural steel, as a pipe-joint cement, and in the manufacture of glass. Litharge, another oxide, is used in assaying as a flux, in rubber manufacture, and in making glass. The acetate, carbonate and other chemical compounds are used in medicine.

The relative amounts of lead consumed in the various uses in 1913 were: In pigment, comprising white lead, red lead, litharge, and orange mineral, 38.0 per cent.; in alloys such as type metal, bearing metals, and solders, 29.7 per cent.; in pipe, 15.2 per cent.; in shot, 10.4 per cent.; and in sheets, 6.7 per cent.

CHANGES IN PRACTICE

The most revolutionary advance in ore dressing of recent years has been the development of oil-flotation, electromagnetic, and electrostatic processes for the concentration of lead-zinc ores. These processes permit the elimination of the objectionable zinc content of many ores and render it an additional credit of great importance in the exploitation of low-grade complex ores.

The Murex process applied to the treatment of complex ores consists of coating the metallic sulphide minerals with oil and particles of magnetite and pyrite roasted to magnetic sulphide, then separating them from the gangue by an electromagnetic machine. The Lyster preferential flotation of galena depends on the presence of various salts in the water used. In the Broken Hill mines these salts are present in the mine waters. After removal of galena the blende may be preferentially floated by the Bradford copper salt or Bradford hyposulphite or sulphurous acid processes.

In the reduction of lead ores, there are improvements constantly being made. These are chiefly in the mechanical appliances, such as mechanical ore hearths and continuous roasting machinery, such as the Dwight-Lloyd, and in details of furnace construction and the handling of materials, rather than in processes or recognized principles. Various new processes have been proposed, most of which are intended to make available the ores now of too low grade, or the complex ores of lead and zinc whose separation is difficult or commercially impracticable. These processes are now the subject of experiment, with some indications that successful applications may be found. One process involves the volatilization by chloridizing roast of sulphide ores, the precipitation of the lead chloride fume by Cottrell electric precipitation, and smelting the fume with lime. At least 50 per cent. of the chlorine is recovered as calcium chloride, which can be substituted for salt in the further operations. With oxidized ores it is proposed to dissolve the lead by means of brine acidified with sulphuric acid and to precipitate metal sponge by electrolysis.

Gillies’s process consists in roasting the complex sulphides to a low sulphur content, mixing with carbonaceous matter, distilling in excess of air, and volatilizing the lead, zinc, bismuth, cadmium, arsenic, etc., as oxides and sulphates, the lead in form of sulphate, the zinc chiefly as oxide. The fume is caught and digested with a solution of ZnSO₄ and free H₂SO₄ from the electrolytic vats; PbSO₄ remains, which can be used as pigment or smelted. The ZnSO₄ solution is electrolyzed, in the presence of gum arabic in the electrolyte, rendering the zinc deposit more dense.

The Ganlin process, reported successful on Burma zinc-lead middlings, consists in feeding the dry pulverized ore into a molten bath of Zn and NaCl in equal parts. Zinc replaces lead and silver, which are dissolved as chlorides, ZnS being precipitated. When this reaction is complete the lead and silver are precipitated as metals by granulated spelter added to the amount of 35 per cent. of their weight, the dissolved spelter forming ZnCl₂. The silver-bearing lead is tapped off, the residue granulated, the salts leached with water, and the zinc-bearing gangue freed from lead shot by tabling, leaving a zinc ore free from lead.

Electrolytic refining has been one of the greatest advances in the industry; it makes possible the preparation of pure lead from any source and the recovery of numerous by-product metals.

GEOLOGICAL OCCURRENCE

Zinc and lead are commonly associated in mineral deposits, sometimes intimately mixed, sometimes segregated enough so that one metal predominates, but seldom free entirely one from the other. The geological and geographical distribution of the two metals is, therefore, nearly identical. Galena is the most common and important of the lead minerals. Cerussite, anglesite and pyromorphite usually result from the oxidation of galena, the sulphate being usually an intermediate state in the oxidation to the carbonate. Pyromorphite and wulfenite are of minor importance. Jamesonite is more an ore of antimony than of lead. Sphalerite (zinc blende) weathers more readily than galena, and therefore zinc in many places is carried below water level more rapidly and completely than lead. For this reason some mines change from predominantly lead mines to zinc mines with greater depth. Apart from the effect of such secondary enrichment, this change is often encountered in primary ores with increase in depth.

Lead ores occur in deposits of several distinct genetic types. Many deposits lie at shallow depth in sedimentary rocks, without apparent connection with igneous rocks, occurring as tabular replacements of receptive beds. In regions of slightly disturbed strata the ore shoots tend to follow pitching troughs. Ores of this type usually contain lead (galena), zinc (sphalerite), and iron (pyrite) minerals; many contain manganese and cadmium; some contain cobalt and nickel; but few carry gold, silver, copper, or antimony. Deposits of this type are of world-wide distribution, and many are extensive and commercially important. The greater purity of the ore and the simplicity of treatment (particularly for the ores in the oxidized zones), caused them to be exploited first and most extensively, and to dominate formerly the world production of lead. To this type belong, with many others, the deposits of the Mississippi Valley and Silesia, that together yielded 15 per cent. of the world’s production in 1913.

Other important deposits are closely associated with igneous rocks, and are characterized by complex ores. They comprise vein deposits, disseminated replacements of igneous rocks, and silver-lead replacements in limestone.

GEOGRAPHICAL DISTRIBUTION

The chief lead-ore deposits of the world are situated in the countries that are listed below in the order of their importance in 1913.

RECOVERABLE LEAD CONTENT OF THE LEAD ORES OF THE WORLD PRODUCED IN 1913[129]

----+-------------------+----------+-----------+-------------
| | | |Percentage of
| | | |world’s total
Rank| Country |Short tons|Metric tons| production
----+-------------------+----------+-----------+-------------
1. |United States | 484,880 | 440,000 | 36.0
2. |Australia | 267,169 | 242,440 | 19.8
3. |Spain | 209,193 | 189,830 | 16.4
4. |Germany | 79,344 | 72,000 | 5.9
5. |Mexico | 68,343 | 62,000 | 5.1
6. |Tunis | 31,076 | 28,200 | 2.3
7. |Italy | 24,905 | 22,600 | 1.8
8. |Canada | 24,244 | 22,000 | 1.8
9. |Austria | 22,591 | 20,500 | 1.7
10. |Great Britain | 20,277 | 18,400 | 1.5
11. |Greece | 19,836 | 18,000 | 1.5
12. |Turkey-in-Asia | 15,428 | 14,000 | 1.1
13. |China | 13,995 | 12,700 | 1.0
14. |German S. W. Africa| 13,224 | 12,000 | 1.0
15. |Algeria | 12,893 | 11,700 | 1.0
16. |France | 9,587 | 8,700 | 0.7
17. |India (Burma) | 6,502 | 5,900 | 0.5
18. |Peru | 4,331 | 3,930 | 0.3
19. |Japan | 4,143 | 3,760 | 0.3
20. |Egypt | 3,196 | 2,900 | 0.2
21. |Russia | 3,083 | 2,800 | 0.2
22. |Bulgaria | 2,204 | 2,000 | 0.2
23. |Sweden | 2,094 | 1,900 | 0.2
24. |Hungary | 1,256 | 1,140 | 0.1
25. |Bolivia | 1,102 | 1,000 | 0.1
26. |Portugal | 661 | 600 |
27. |Rhodesia | 361 | 330 |
| +----------+-----------+-------------
| Total |1,345,918 | 1,221,390 | 100.0
----+-------------------+----------+-----------+-------------

[129] Adapted from compilations by Adolph Knopf, of the U. S.
Geological Survey.

The four districts now of pre-eminent importance are, in order, Broken Hill in New South Wales, Australia; southeastern Spain; southeastern Missouri and Coeur d’Alene, in Idaho: which are credited respectively with about 19, 16, 12 and 10 per cent. of the world’s production in 1913.

=United States.=--The chief producing regions and their percentage of the domestic lead production in 1915 are as follows:

Percentage of total
Region domestic production
Southeastern Missouri 33
Coeur d’Alene, Idaho 27
Utah 18
Joplin (in Mo., Kans., Ark., and Okla.) 6
Colorado 5

As regards the types of ores and the character of the lead produced, there are two metallographic provinces: the Mississippi Valley, including southeastern Missouri and Joplin, and the minor district of Wisconsin, producing as soft lead 39 to 45 per cent. of the total domestic production; and the Western province, in which the ores are complex, carrying precious metals and often antimony and copper. All of the output from the Western province, but only a part of the soft lead, is desilverized.

Ninety per cent. of the ore mined in southeastern _Missouri_ comes from St. Francois and Madison counties. The ore deposits contain predominantly galena, and are disseminated in Cambrian limestone over large areas at depths of 100 to 550 feet. Copper, nickel, and cobalt occur in the Madison County ores, and copper concentrates are separated and shipped by nearly all the companies in the region. The principal operating companies, with the names of companies absorbed by them or now subsidiaries, shown in parenthesis, are: St. Joseph Lead Co. (Doe Run Lead Co.), Federal Lead Co., National Lead Co. (St. Louis Smelting & Refining Co.), Desloge Consolidated Lead Co., Baker Lead Co. (St. Francois Lead Co.), Boston Elvins Lead Co., Missouri Metals Co. (Mine La Motte Co.), and Missouri Cobalt Co. (North American Lead Co.). The St. Joseph Lead Co. is normally the second largest lead-producing company in the United States. Its holdings have a conservatively estimated life of 20 years, at a rate of production of 2,000,000 tons of ore, or 80,000 short tons of lead, per annum. In 1917 this company mined 2,485,431 tons of ore, nearly half the total output of the region. The Federal Lead Co., a subsidiary of the American Smelting & Refining Co., is the next largest producing company in the region. In 1915 it mined and milled 1,355,000 tons of ore. The National Lead Co., through its subsidiary, the St. Louis Smelting & Refining Co., works three mines near Flat River and has a concentration plant with a daily capacity of 2,400 tons. Its smelter at Collinsville treats its own concentrates, as well as those of the Baker Lead Co. and the Boston Elvins Lead Co. The Desloge Consolidated Lead Co. operates three mines and a mill of 1,700 tons’ daily capacity; its ores are smelted by the Federal Lead Co. The Missouri Metals Co. operates the Mine La Motte and a mill treating 700,000 tons annually at the 1917 rate. In 1915 it was estimated that this mine could produce 3,000,000 tons of ore annually for sixty years.

In the Joplin region, which is chiefly in Missouri but also includes adjacent areas in Kansas, Arkansas, and Oklahoma, the ores lie at three horizons in horizontal limestone and chert beds of Lower Carboniferous age. At the upper horizon, usually 100 to 150 feet below the surface, the ore occurs in clayey chert breccias. The ore bodies are characteristically “runs” up to 300 feet wide, and continuous in one horizon for several hundred feet and, rarely, for more than a mile. The middle horizon, or “sheet ground,” at a depth of 150 to 300 feet usually ranges from 6 to 15 feet in thickness. The ore, mixed galena and blende, cements brecciated chert. The third and lowest horizon, in sandy limestones, contains disseminated ores mainly, and as yet is little exploited. In 1915, about 4,000,000 tons of ore was mined from the upper horizon, and 6,500,000 tons from the middle horizon or “sheet ground.” The average lead content of the ore as mined was about 0.25 per cent. Most of the lead concentrates are sold in open market. The Webb City district is the most important in the Joplin region, and the American Zinc, Lead & Smelting Co. is the largest galena producer. Most of the output is by lessees and small operators. The Joplin district ranks second in importance. The A. W. C. Mining Co. is the largest miner of “sheet ground.” The Ravenswood and Ritz mines of the United States Smelting, Refining & Mining Co., in Jasper County, produce 218,000 tons of ore annually. The concentrates of this region are chiefly smelted by the plants of the Eagle-Picher Lead Co. at Galena, Kansas; Joplin, Missouri; Webb City, Missouri; and by the Granby Mining & Smelting Co. at Granby, Missouri.

The Coeur d’Alene region is in Shoshone County, _Idaho_. The deposits are metasomatic veins formed by replacement of siliceous sedimentary rocks along zones of fissuring, and carry mainly galena and siderite with some pyrite and sphalerite. In 1915 the crude ore shipments amounted to 95,169 tons with a lead content of 35,271 short tons. The remainder of the ore, or nearly 96 per cent. of the total, is concentrated to carry about 50 per cent. lead. The 1915 yield of concentrates of all kinds amounted to 329,530 tons, having a lead content of 128,928 short tons, making the total lead content of crude and concentrate shipments 164,199 short tons. The mining companies form three groups, determined chiefly by their relations or affiliations with the smelters, as follows: The Bunker Hill group, comprising the Bunker Hill & Sullivan Mining & Concentrating Co., and the Hecla Mining Co.; the Day group, comprising the Tamarack & Custer Mining Co., the Amazon-Manhattan mine, and the Hercules Mining Co.; and the American Smelting & Refining group, comprising the Federal Mining & Smelting Co. and various small producers.

The mines of the Bunker Hill & Sullivan Mining & Concentrating Co. had reserves on December 31, 1917, of 3,457,634 tons. The ore bodies are replacements of quartzite. This company’s production in 1917 was 493,030 tons of ore, the metallic lead recovered by smelting being 46,996 tons. The Bunker Hill & Sullivan Co., while still shipping its own ores to the Helena plant of the American Smelting & Refining Co., built its own smelter at Kellogg, Idaho, where it smelts the Hecla and other ores. The Day family controls the Hercules, and Tamarack & Custer companies, the Northport smelter at Northport, Washington (now closed down), and the Pennsylvania Smelting & Refining Co. at Pittsburgh, Pa. The 1916 shipments of the Hercules had a lead content of about 22,000 tons. Both companies are close corporations and make public little information as to their operations. The Tamarack & Custer probably has large reserves of ore averaging about 9 per cent. lead; it has produced as much as 3,000 tons of shipping ore and concentrates per month. The Federal Mining & Smelting Co. operates several mines. One-sixth of the stock is owned by the American Smelters Securities Co. and all its silver-lead ores and concentrates are contracted to the American Smelting & Refining Co. The Success Mining Co., working two mines, has been an important producer. The Interstate-Callahan has been chiefly a zinc producer but ships some lead concentrates to the Salida plant of the Ohio & Colorado Smelting Co.

The lead production of _Utah_ is chiefly from the Park City, Bingham Canyon, and Tintic districts. The ores, composed of galena, tetrahedrite and pyrite, and in places sphalerite, with their oxidized derivatives, occur in lodes cutting limestones, sandstones and shales, chiefly of Carboniferous age, and also as bedded deposits in limestone. Both types are frequently associated with porphyry and form irregular ore bodies in contact-metamorphosed limestone. In many mines copper is an important constituent of the ores and the silver content is always important.

The production of _Colorado_ in 1917 comprised 33,995 short tons of lead, of which 9,293 short tons came from the Leadville district in Lake County, 10,412 short tons from the San Juan district in San Juan, San Miguel and Ouray counties, and 6,816 tons from the Aspen district in Pitkin County. The Leadville deposits are in the Mosquito range. The chief producing companies are the Iron Silver Mining Co., the Yak Mining, Milling & Tunnel Co. and its subsidiary, the Leadville Exploration & Mining Co.; the Western Mining Co.; the Downtown Mines Co.; the Ibex Mining Co.; and the United States Smelting, Refining & Mining Co. The Yak Mining, Milling & Tunnel Co., and the Western Mining Co. are subsidiaries of the American Smelting & Refining Co. In the San Juan district, the principal producers are the Liberty Bell; Smuggler-Union; Tomboy; Black Bear; Iowa-Gold Tiger; Dives; Shenandoah; and Silver Lake mines. The veins penetrate all the clastic and igneous rocks of this region, and the ores are exceedingly complex. In Pitkin County, the Smuggler Leasing Co. operates most of the producing mines at Aspen. The ores are peculiarly free from other metals than lead, antimony, and silver.

=Australia.=--The lead resources of the Commonwealth of Australia are chiefly in New South Wales, Western Australia, Tasmania, and Queensland. New South Wales has been the chief producer in the past, but the Tasmanian deposits are now being rapidly developed and equipped for production.

The most important source of ore in _New South Wales_ is the great Broken Hill lode, situated in the arid Barrier Ranges at an elevation of about 1,000 feet above sea level. The lode ranges in width from a few inches to 400 feet and has been worked over a distance of three miles. Mining began in 1884 and now is conducted by several mining companies which, in the order of the importance of their production and ore reserves, are: Broken Hill South Silver Mining Co.; Broken Hill North Mining Co.; Zinc Corporation; Sulphide Corporation; British Broken Hill Proprietary Co.; Broken Hill Proprietary Co.; Broken Hill Proprietary Co., Block 10; and Broken Hill Proprietary Co., Block 14.

Although the deepest workings are 1,815 feet deep, the ore still continues downward. For many years the estimated ore reserves of all the mines have approximated 12,000,000 tons. The upper part of the lode consisted of a gossan 20 to 100 feet wide of siliceous and manganiferous limonite, hematite, and kaolin. Below the gossan were great masses of cerussite, anglesite, cuprite, and malachite, with abundant cerargyrite, embolite, and iodyrite. Between the oxidized and primary sulphide ores was a thin zone of secondary sulphides. The early operations in the district were conducted for the purpose of obtaining lead ores, and immense dumps were accumulated of zinc-bearing ores sorted out or zinc-bearing tailings left after concentration of the lead ores. In 1903 these dumps were estimated at 5,687,400 tons, carrying 18.6 per cent. zinc. With the development of a demand for zinc sulphide ores and of oil-flotation methods of separation and concentration, these dumps have been important sources of zinc. There are two classes of sulphide ores, distinguished as silicate gangue ore, and calcite gangue ore. The sulphide ores are a close mixture of galena and zinc blende, carrying silver. The silicate gangue ore bodies carry rhodonite, garnet, and quartz; and are richer in zinc and silver than those with calcite gangue.

The Broken Hill South Silver Mining Co. has ore reserves estimated at 3,350,000 tons and is the largest ore producer in the field. Broken Hill North, Broken Hill South, Amalgamated Zinc (De Bavay), Zinc Corporation, and Barrier South, Ltd., are controlled by the Hoover-Govett-Bailliau group of British and Australian capitalists.

The Amalgamated Zinc Co. in 1913 treated 498,289 tons of tailings containing 17.1 per cent. zinc, 3.7 per cent. lead, and 4.4 ounces silver, obtaining 140,098 tons zinc concentrates carrying zinc, 48.9 per cent., lead 5.9 per cent., and silver 8.5 ounces per ton. The Zinc Corporation, a company formed by Bewick, Moreing & Co., has ore reserves estimated at 1,504,211 tons, averaging 14.8 per cent. lead, 9.2 per cent. zinc, and 2.5 ounces of silver per ton.

The largest lead-producing district of _Tasmania_ is on the West Coast, where the largest producers, the Hercules of the Dundas group and the Primrose and Tasmanian copper mines of the Rosebery company group, are now controlled by the Mount Read-Rosebery Co., affiliated with the Mount Lyell Mining & Railway Co., Ltd. The deposits contain complex sulphide ores, the reserves being estimated by the state geological staff at 1,272,500 tons, averaging 29.79 per cent. zinc, 8.89 per cent. lead, 12.16 ounces of silver, and 0.17 ounces gold per ton. This estimate has since been revised and made more conservative.

In 1913 _Western Australia_ produced 26,589 long tons of lead ore and 125 tons of silver-lead ore, almost wholly from the Northampton district on the West Coast. The only company working on a large scale is the Fremantle Trading & Smelting Co., operating the Baddera and Narra Tarra mines and, formerly, a smelter at Fremantle. The Chillagoe district is the largest producer in _Queensland_, its output amounting to 2,550 long tons of pig lead in 1913, chiefly from the Girofla mine of the Mungana company, but in part from lead-copper concentrates. The Chillagoe operated a small smelter. The total pig lead production of Queensland was 3,603 long tons in 1913.

=Spain.=--Spain yielded in 1913, 314,369 short tons of lead concentrates, from which were smelted 189,559 tons of pig lead. In 1915 only 1,010 short tons of ore or concentrates was exported, and 161,912 short tons of desilverized lead was exported, mostly to England. Over 90 per cent. of the production of ore came from the provinces of Jaen, Murcia, Cordoba, and Ciudad Real. In 1913 the Province of Almeria occupied fourth place, but its mines are now nearly exhausted. These provinces are in the southeastern part of Spain and cover the Sierra Morena and Sierra Nevada mountain ranges.

In the Province of Jaen are two principal districts--the Linares-Santa-Elena and the La Carolina. Many years ago Linares was the greatest lead-producing district in the world. The veins cut granite and thin overlying sandstone and are very narrow. The Arrayanes, a state-owned mine, has been exploited over a length of two and a half miles and to 1,500 feet in depth. The gangue is granite, quartz and calcite. Iron and copper pyrites and sphalerite are present, but a 79 per cent. lead concentrate is easily made. The deepest mine is 1,800 ft. deep and is still in rich ore. In the Santa Elena vicinity, the San Fernando, Ojo Vecino, and Santa Ana mines are owned locally. The Caridad is owned by French capital and the Santa Susanna by a Belgian concern, the Compagnie Real Asturienne des Mines. In La Carolina district the nearly vertical lodes cut Silurian quartzites and Cambrian and Silurian slates. The ore attains a greater width than in the veins of the Linares district. The Nuevo Centenillo mine (English owned) produces 27,000 short tons of concentrates annually. The great Guindo lode runs through six mines, two of which are owned by Spanish companies, and three by the Guindo Co., a German-Spanish corporation having an output of 27,000 short tons of concentrates yearly. The Castillo La Vieja, owned by a French company, has a yearly output of 20,000 tons of marketable ore.

In the Province of Murcia the Mazarron and Cartagena districts are important. Most of the veins are nearly vertical but many have spurs or branches forming lenticular and bedded deposits in the sedimentaries. This district extends southwestward along the coast from Cabo de Palos a few miles north of Cartagena. The production of this province has been steadily decreasing.

In the Province of Cordoba (district of Posadas) many silver-lead-zinc mines were worked by the Romans and are still profitable. Near Alcaracejos are the mines of Anglo-Vask and Penarroya, the latter owned by a French company of the same name.

The development of the lead ores in the Province of Ciudad Real has been retarded by lack of transportation facilities. The best known district is that of El Hoyo-San Lorenzo, which in 1915 had risen to fourth place among the lead-producing districts of Spain.

=Germany.=--In imperial Germany the lead-producing districts in the order of their importance were as follows: Upper Silesia, Rhenish Prussia, Westphalia, Saxony, Hanover, and Nassau. Rhenish Prussia and Westphalia are usually grouped together as one metallographic province. At Gladbach, east of Cologne in _Rhenish Prussia_, are ore deposits lying in troughs and basins in limestone. The ore is smithsonite and galena mixed with shale. The chief deposits of _Westphalia_ are at Iserlohn and Brilon. At Iserlohn ores containing calamine, galena, and blende are found in irregular pockets. The deposits of Brilon are similar, but most of the ore is found in crevices in the limestone. Rhenish Prussia and Westphalia are the source of about one-third the German production of lead.

The greater part of _Upper Silesia_ lay within the boundaries of Germany in 1914, although formerly part of the kingdom of Poland, the population being still predominantly Polish; but portions were included in the old empires of Russia and Austria. The pre-war production of lead ores from Russian Poland was entirely from this metallographic province. The deposits, which contain lead and zinc together, lie in Triassic beds that overlie Carboniferous rocks carrying important seams of coal. This juxtaposition of ore and fuel furnish an ideal basis for the great smelting industry that developed locally, for the conditions permit smelting of low-grade ores.

The historic mines at Freiberg, in _Saxony_ (Erzgebirge) yield a small quantity of blende in connection with the concentration of galena ores from a remarkable series of intersecting veins, which number more than 900, although few are more than 2 feet thick. They have been worked to a depth of 2,100 feet. More than 10 per cent. of the lead production of Germany is derived from Saxony. These mines are owned and operated by the Saxon government, which also owns the smelting plants.

Lead predominates over zinc in the ores of the Upper Harz, in _Hanover_. These ores occur in veins and zones in slates of Devonian and Lower Carboniferous age. These mines are worked by the Prussian Department of Mines, which also operates two smelting plants, the output being about 10 per cent. of the total German output. In _Nassau_, in the valley of the Lahn, lead ores are produced as a by-product, with zinc blende concentrates.

=Mexico.=--In Mexico lead ores are mined in several states, the more important being Chihuahua, Durango, Coahuila, Nuevo Leon, Sonora, San Luis Potosi, and Zacatecas. In many districts during a considerable part of the past eight years work has been intermittent and occasionally suspended for long periods.

The Santa Eulalia district in _Chihuahua_ is largely owned by American companies, including the American Smelting & Refining Co., operating the Mina Vieja, Sin Nombre, Velardeña, San Antonio and Santo Domingo mines; and El Potosi Mining Co., operating the mines of the same name. The San Toy is under lease to the American Metal Co., now purged of German interests. The Santa Eulalia Mining Co. belongs to the Hearst estate. The Buena Tierra Mining Co. is a British concern. The mines of the Santa Barbara and Parral districts are also largely under American control, among many others being the Montezuma Lead Mining Co. of the R. S. Towne interests, Granadeña Mining Co., American Smelters Securities Co. and American Zinc Extraction Co. The American Smelters Securities Co. operates the Tecolotes, Montezuma, San Diego, Guadalupe and Alfarena mines. The San Francisco mines are owned by British capital. In the San Isidro district the Calera, Prieta and Buena Vista mines are operated by the American Smelting & Refining Co. The Lago mine is operated by C. M. de Las Plomosas (French). In the Parado district are mines of the Compañia Minera Aurora y Anexas, controlled by the Madero family (Mexican). Other Chihuahua mines of the American Smelting & Refining Co. are Orizaba and La Union at Magistral, the Jibosa at Dolores, La Luz and Parcionera at Cordera, the Veta Grande and Veta Colorado.

The largest operators in the state of _Durango_ are the American Smelters Securities Co. at Velardeña and the Cia. Minera de Peñoles at Mapimi, both now American since the selling of the German-held stock of the American Metals Co. by the Alien Property Custodian.

In _Sonora_, the Carnegie Lead & Zinc Co. worked a mine near Cananea, during the war, but the best part of the deposit is now depleted.

The Tiro General mines, in _San Luis Potosi_, belong to the American Smelting & Refining Co.

The Cabrilla and Paloma mines, in the Cabrillas district in _Coahuila_, are owned by the Compañia Minera de Peñoles, controlled by the American Metal Co. The Sierra Mojada district is dominated by American companies, the principal mines being owned by the Consolidated Kansas City Smelting & Refining Co., a subsidiary of the American Smelting & Refining Co. The Boquillas de Carmen mine has been acquired by an American company.

In the state of _Nueva Leon_, deposits lying within a radius of 50 miles of Monterrey, at Villadama, Vallecillo, Ladera Occidental de Minas Viejas, etc., have been exploited by German and American companies, including the Compañia Metalurgica Mexicana (American), Joplin-Mexican Mining Co. (American), and the Metallgesellschaft (German).

=Other Countries.=--The output of lead ore in _Tunis_ in 1913, almost wholly by French companies, was 56,072 metric tons. It is all exported.

Practically all the output of lead ore in _Italy_ is derived from the Inglesias district of Sardinia, which in 1915 produced 40,829 metric tons of ore averaging 55 per cent. lead, out of a total national production of 41,590 metric tons. The principal operators are the Monteponi and Pertusola companies, the former Italian, the latter English. The remainder of the ore comes from the provinces of Bergamo, Brescia Cuneo, and Grosseto, and the operating companies are the English Crown Spelter Co. (English), and the Societa Austro-Belga and Société de la Vieille Montagne (Belgian).

In _Czecho-Slovakia_, the most important district is that of Przibram, in Bohemia. Rich lead ores were once mined at Mies, but the district is now exhausted. The district of Joachimsthal was for centuries an important producer.

In _German-Austria_ are the silver-lead mining districts of Schneeberg, in Tyrol, and Raibl, in Upper Carinthia. In both districts the mines were before the war owned and operated by the Austrian state. Miess, in Carinthia, is one of the chief sources of ore in recent years.

The lead mines of _Great Britain_ in 1916 produced 17,083 tons of dressed lead ore. The largest operator is the Weardale Lead Co., operating the Boltsburn and Stanhopeburn mines and smelting its own and some custom ores.

In _Greece_ the only important lead deposit is that of Laurium, which was worked on a large scale in ancient times. It is now controlled and operated by a French company, the Compagnie Française des Mines de Laurium.

The lead production of _Canada_ is chiefly from British Columbia, the most important producers being in the Slocan district. The largest operator is the Consolidated Mining & Smelting Co. of Canada, Ltd., proprietor also of the Trail smelter. This company operates the Sullivan and other mines and produced during the year ended September 30, 1917, 29,542 tons of lead ore from the Sullivan mine, and 1,100 to 1,500 tons from several others. The Sullivan mine has been reported to have reserves of 3,500,000 tons of galena-sphalerite ore. Numerous smaller properties in the same district ship ore to the Trail smelter, which produced some 22,000 tons of lead during the year ended September 30, 1917.

The most important lead-silver mines of _Asiatic Turkey_ are those at Hodsha Gernish (Balia), belonging to the Société des Mines de Balia-Kara-Aidin (French), which yield about 12,000 tons of lead annually. There is a state-owned mine at Bulgardagh producing lead, gold, and silver. The English company, Asia Minor Mining Co., produces about 3,000 tons of ore annually.

In _China_ the ten lead mines in the Province of Hunan are controlled by Chinese. The Wah Chang Mining & Smelting Co., Ltd., operates the Tien For Tai mines. The Shui-Ko-Shan mine, controlled by the Hunan Mining Board, from a deposit in limestone, produced in 1913, 51,561 net tons of ore, which yielded 3,762 tons of lead concentrates and 12,275 tons of zinc concentrates. Since 1913 the production has been increased, but the possibilities of the deposit are limited. The Japanese have endeavored to secure control of this mine, but without success. The pig-lead output of China is chiefly consumed in the country. The only modern lead smelter is at Changsha and is owned by Japanese.

The lead production of _Southwest Africa_ (formerly German) has been derived chiefly from the Tsumeb deposit in the Grootfontein district in the Otavi Mountains. The ores exported in the fiscal year 1913-14 amounted to 48,000 long tons, averaging 13 per cent. copper, 25 per cent. lead, and 7.7 ounces silver. The ore is a coarsely crystalline aggregate of argentiferous galena and chalcocite with minor amounts of other minerals. The Otavi Mines & Railway Co. owns and operates this mine, the ore having been exported in 1913-14 to the United States for smelting.

In 1913 all the lead-ore production of _Algeria_ was from the Department of Constantine, and amounted to 21,442 tons. Practically the whole production was by French companies.

Lead ore is produced in several scattered districts in _France_, chiefly in the south. Among the mines are the Chaliac et Chassezac (Ardeche) mines of the Société Metallurgique et Minière des Cevennes, producing 2,200 metric tons in 1913; the mines of the Société Civile des Mines des Malines; La Londe mine of the Société des Mines des Bormettes; that of the Société des Mines de Bleymard, producing 2,470 tons of galena ore in 1913; and the Pierrefitte (Haute Pyrenees), Peybrune, and Bulard de Sentein-Saint Lary (Ariege) mines. All of these appear to be French companies, except the Pierrefitte, which is English controlled.

In _Burma_, the chief deposits are those of the Bawdwin mines, in the Northern Shan States (Burma), now connected with the Burma Railway from Rangoon. The ore bodies of present interest are nearly vertical shoots in a feldspathic grit (rhyolitic tuff or silicified rhyolite) and rhyolite series. The Chinaman and the smaller Shan ore body are believed to have been one, though now separated by faulting. Estimated reserves on December 31, 1917, were 4,033,000 tons of lead-zinc ore assaying 24.7 ounces of silver, 27.4 per cent. lead, 19.1 per cent. zinc, and 0.4 per cent. copper; and 105,000 tons of copper-silver ore assaying 21.0 ounces of silver, 19.9 per cent. lead, 8.8 per cent. zinc, and 8.9 per cent. copper. Since then development has considerably increased these reserves. In addition there is estimated to be 1,600,000 tons of low-grade ore averaging 5.1 ounces of silver, 7.5 per cent. lead, 4.8 per cent. zinc, and 0.2 per cent. copper per ton, with excellent prospects of larger developments. A large tonnage of gossan outcrop ore containing 4 or 5 ounces silver, 4 to 5 per cent. lead, and a little zinc is cheaply mined and available as siliceous flux. The essential constituents of the ores are galena and sphalerite with a little pyrite and chalcopyrite. All of the ore is argentiferous.

The lead and zinc concentrates are available for the customary methods of smelting. A zinc-distilling and sulphuric acid plant is being constructed at Sakchi, with the aid of the Indian government, to treat the table zinc concentrates. Its initial capacity of 25,000 tons of concentrates is expected to be increased to 75,000 tons. The company operates a lead smelter at Nam-Tu, 11 miles from the mines, using a mixture of ore and ancient slags. Treatment of the middlings by the Ganlin process is proposed and a 100-ton unit is under construction at Avonmouth, England. The Bawdwin deposits may be expected to be an important factor in the world’s production of lead in the immediate future. They are owned by the Burma Mines, Ltd., an English corporation representing the R. Tilden Smith-Govett-Hoover interests and some American capital.

The lead production of _Peru_ is largely in the form of ancient high-lead slags from the Cerro de Pasco district, Department of Junin, shipped to plants of the American Smelting & Refining Co. in the United States. Lead occurs as a minor constituent of copper deposits.

The domestic lead-ore deposits of _Japan_ are all owned and operated by Japanese. During the war Australian concentrates and Chinese ore were imported and smelted, 10,666 short tons of the former, carrying 56 per cent. lead, during the fiscal year 1915-16, and 9,829 short tons of the latter during the year 1916. The Fujita company, mining in Japan, Korea, and Formosa, produces 382 short tons of lead yearly. Its principal mine is the Kosaka, at the northern end of Hondo, the main island of Japan. The ore is a complex sulphide mixture of lead, zinc, iron, and copper minerals. The annual output of this mine is about 335 short tons of lead. The Mitsui Mining Co., Ltd., is the largest producer, its output in 1915 having been 3,561, and in 1916, 8,098 short tons of pig lead. This is derived wholly from the Kamioka zinc-lead mine, in the Province of Hida, on a contact metamorphic deposit in limestone lenses enclosed in Archean gneiss near a quartz porphyry contact.

The only deposit exploited in _Egypt_ is that known to the ancients, Gebel Rosas, now operated by the French company, Compagnie Française des Mines de Laurium. As regards the former empire of _Russia_, the lead production of _Russian Poland_ and the Caucasus Mountains is small, the output in 1913 coming chiefly from the Caucasus Mountains and being made by the Elboruss Co., and the Compagnie d’Alagir (Belgian).

In the Altai Mountains, in _Siberia_, a zinc-lead-silver deposit, the Zmeinogorsk, formerly belonging to the Russian Mining Corporation (British), is now owned by a Russian company, Altai Mines, Ltd., though part of the capital is probably British. The Nerchinski district, in eastern Siberia, comprises many known deposits. The Akatonevski, Kadaenski, Algachinski and Klichinski deposits are veins, whereas many of the Zerentniski, Gasimoura Valley, Koultoumski and Maltzevski are lenticular masses of disseminated ore. In the Kadaenski deposits two massive disseminated ore bodies occur in dolomite between two veins. These deposits were controlled by the Imperial Cabinet, and their exploitation was being seriously considered by British and American capital shortly before the revolution. The deposits of largest present importance in Siberia are those of the Ridder Mining Co., controlled by the Irtysh Corporation of London, which has developed two mines, the Ridder and the Sokolni, on the same mineralized zone. The deposits are replacements by complex sulphide ore of members of a conformable series of slates, tuffs, and igneous sills. In 1916 the reserves were estimated at 945,000 tons of a grade of 31.2 per cent. zinc, 18.1 per cent. lead, 1.5 per cent. copper, 9.7 ounces of silver, and 0.47 ounces of gold; and also 2,229,000 tons averaging 6.7 per cent. zinc, 3.5 per cent. lead, 0.5 per cent. copper, 1.7 ounces of silver, and 0.7 ounces of gold per ton. Other known mineralized zones have not been developed, but the possibilities of the property are immense, being limited chiefly by general political and economic conditions.

A small quantity of lead is produced in _Bulgaria_ from a few small deposits containing intimate mixtures of lead, copper and zinc minerals; usually either zinc or copper predominate.

The most important lead deposit in _Sweden_ is the Sala, in Vestmanland, where irregular masses and veins of galena and blende with minor amounts of pyrite, etc. occur in limestone. Similar deposits occur at Lofas and Guldmedshyttan.

_Hungary_ has no lead mines of importance, although galena occurs in some of the veins exploited, notably at Schemnitz, where the larger mines are the property of the Hungarian state.

Most of the ore from _Bolivia_ exported to the United States comes from the Majo mine, which produced 884 tons, lead content, in 1912. This mine is in southern Bolivia in the region of La Quiaca.

The most important lead-producing area in _Portugal_ is Merlota, near the Guadiana River, where silver-bearing galena and oxidized ores are found. Other districts are those of Villa Real, Vizen, Aveiro, Portalagre, and Beja. The deposits are similar to those of Spain.

The only deposit of importance in _Rhodesia_ (South Africa) is the Rhodesia Broken Hill. The large ore bodies are, so far as developed, almost wholly oxidized. One ore body is estimated to contain 250,000 long tons of ore averaging 26 per cent. lead and 22.5 per cent. zinc; another ore body is estimated to contain 300,000 long tons, averaging 32 per cent. zinc, with little lead, but much iron oxide and carbonate. These ore bodies are controlled by British capital. Considerable difficulty has been experienced in developing a commercial treatment. Reports indicate this deposit is of greater magnitude than is generally recognized.

The most important lead deposit of _Belgium_, or rather of the neutral district of Moresnet adjoining Belgium, belonged to the Belgian company, Société de la Vieille Montagne at Moresnet. It was exhausted in 1882.

=Changes in Geographical Distribution of Production in the Near Future.=--No marked change in the pre-war rate of production of ores by the countries of Europe or northern Africa is anticipated when normal conditions are resumed. Most of the districts in those countries have been exploited a long time and have passed their zenith of production; many are approaching exhaustion. A possible exception to this statement is the Ciudad Real Province of Spain, which is being energetically developed by the Penarroya company. The division of Austria-Hungary will not materially affect the control of the lead industry.

The United States will continue to be the largest source of lead in the world, and the only change anticipated is a slight increase in the relative importance of the hard-lead output of the Western States.

The chief new factor in production will be the Bawdwin mines of Burma, which are being developed on a large scale for the production of 300,000 tons of ore annually.

Recent developments in the Altai Mountains of southwestern Siberia have proved immense bodies of complex zinc-lead ores. Their geographic isolation will prevent them from becoming an important factor in the world market for a long period, notwithstanding their large size and excellent grade. The extent of their exploitation will be determined largely by how far the Russian market is affected by internal social and political conditions. The loss of the Polish industrial region, with its market protected by stringent tariffs, materially restricts the extent of visible outlets.

In the future, but not soon, it is anticipated that there will be developments in the Andes region of South America of complex lead-ore deposits similar to those of the Western United States.

POLITICAL CONTROL

Political control of the lead resources of the world up to the outbreak of the war in 1914 seems to have been a minor factor in the industry, and to have made itself felt chiefly through imposition of protective tariffs or bonuses designed to stimulate domestic production, smelting, and refining. Such measures resulted in the establishment of lead smelting in British Columbia and were an inducement to the development of the Altai district of Siberia. As will be described later in detail, the growth of international commercial relations had permitted the establishment by German interests of organizations which, although not all-inclusive, gave effective control of the industry.

During the World War, however, political jurisdiction was largely invoked to restore control of national resources to citizens. This movement was particularly marked in the British Empire, where there now exists a joint political and commercial control. Alien interests have been eliminated by governmental action and the government retains a share in the control through its interest in marketing organizations or its financial participation in reduction works. In France, the consortium Société Minerais et Metaux, organized by government action, is the arbiter of the industry and comprises all the important French companies both at home and abroad. In the United States the Alien Property Custodian was active in eliminating all enemy-alien interests.

COMMERCIAL CONTROL

Copper, lead, and zinc form a class by themselves, with respect to industrial utility and tonnage produced, ranking after iron, which far outclasses them, as the most important base metals. The total yearly production of each throughout the world is considerably more than a million tons.

TABLE 53.--ORE PRODUCTION, SMELTING, AND CONSUMPTION OF LEAD IN 1913

(Tons of 2,000 Pounds)

-------------------+-------------------------------------------+
| Recoverable lead content of ores |
| and concentrates |
+---------------+-------------+-------------+
| | | |
|Mine production| Exports | Imports |
+---------+-----+-------+-----+-------+-----+
| | Per| | Per| | Per|
| Net |cent.| Net |cent.| Net |cent.|
Country | tons |[130]| tons |[130]| tons |[130]|
-------------------+---------+-----+-------+-----+-------+-----+
Algeria | 12,900| 1.0| 12,900| 1.0| ... | ...|
Australia | {244,500| 19.7|132,000| 10.6| ... | ...|
| { [133]| | | | | |
Austria-Hungary | 23,800| 1.9| ... | ...| 2,800| 0.2|
Belgium | ... | ...| ... | ...| 56,000| 4.5|
Bolivia | 1,100| 0.1| 1,100| 0.1| ... | ...|
Bulgaria | 2,200| 0.2| 2,200| 0.2| ... | ...|
Canada | 18,800| 1.5| ... | ...| ... | ...|
China | 14,000| 1.1| 14,000| 1.1| ... | ...|
Egypt | 3,200| 0.3| 3,200| 0.3| ... | ...|
France | 9,600| 0.8| ... | ...| 21,300| 1.7|
German S. W. Africa| 13,200| 1.0| 13,200| 1.0| ... | ...|
Germany | 79,300| 6.4| ... | ...|120,300| 9.7|
Great Britain | 20,300| 1.6| ... | ...| 13,300| 1.1|
Greece | 20,300| 1.6| ... | ...| ... | ...|
Holland | ... | ...| ... | ...| ... | ...|
India | | | {[134]| | | |
(Burma) | 6,500| 0.5| {2,200| 0.2| ... | ...|
| | |{ [134]| | | |
Italy | 24,900| 2.0|{ 1,000| 0.1| ... | ...|
Japan | 4,200| 0.3| ... | ...| ... | ...|
Mexico | 68,300| 5.5| 7,100| 0.6| ... | ...|
Norway | ... | ...| ... | ...| ... | ...|
Peru | 4,300| 0.3| 4,300| 0.3| ... | ...|
Portugal | 600| ...| 600| ...| ... | ...|
Rhodesia | 400| ...| 400| ...| ... | ...|
| | | {[134]| | | |
Russia | 3,100| 0.2| {2,000| 0.2| ... | ...|
Spain | 209,200| 16.8| ... | ...| 9,900| 0.8|
Sweden | 2,100| 0.2| 500| ...| ... | ...|
Switzerland | ... | ... | ... | ...| ... | ...|
Tunis | 31,100| 2.5| 31,000| 2.5| ... | ...|
Turkey-in-Asia | 15,300| 1.2| ... | ...| ... | ...|
United States | 411,900| 33.3| ... | ...| 13,200| 1.0|
Other countries | ... | ...| ... | ...| 2,600| 0.2|
-------------------+---------+-----+-------+-----+-------+-----+
World[135] |1,245,100|100.0|227,800| 18.2|239,400| 19.2|
-------------------+---------+-----+-------+-----+-------+-----+

-------------------+-------------------------------------------+
| |
| Primary pig lead |
+---------------+-------------+-------------+
| Smelter | | |
| production | Imports | Exports |
+---------+-----+-------+-----+-------+-----+
| | Per| | Per| | Per|
| Net |cent.| Net |cent.| Net |cent.|
Country | tons |[130]| tons |[130]| tons |[130]|
-------------------+---------+-----+-------+-----+-------+-----+
Algeria | ... | ...| ... | ...| ... | ...|
Australia | 112,500| 9.0| ... | ...|101,900| 8.1|
| | | | | | |
Austria-Hungary | 26,600| 2.1| 12,500| 1.0| ... | ...|
Belgium | 56,000| 4.5| ... | ...| 8,700| 0.7|
Bolivia | ... | ...| ... | ...| ... | ...|
Bulgaria | ... | ...| ... | ...| ... | ...|
Canada | 18,800| 1.5| 6,400| 0.5| ... | ...|
China | ... | ...| ... | ...| ... | ...|
Egypt | ... | ...| ... | ...| ... | ...|
France | 30,900| 2.5| 87,700| 7.0| ... | ...|
German S. W. Africa| ... | ...| ... | ...| ... | ...|
Germany | 199,600| 15.9| 46,800| 3.7| ... | ...|
Great Britain | 33,600| 2.7|177,400| 14.1| ... | ...|
Greece | 20,300| 1.6| ... | ...| 20,300| 1.6|
Holland | ... | ...| 10,500| 0.8| ... | ...|
India | | | | | | |
(Burma) | 4,300| 0.3| ... | ...| 4,300| 0.3|
| | | | | | |
Italy | 23,900| 1.9| 12,000| 1.0| ... | ...|
Japan | 4,200| 0.3| 17,000| 1.3| ... | ...|
Mexico | 61,200| 4.9| ... | ...| 61,200| 4.9|
Norway | ... | ...| 500| ...| ... | ...|
Peru | ... | ...| ... | ...| ... | ...|
Portugal | ... | ...| ... | ...| ... | ...|
Rhodesia | ... | ...| ... | ...| ... | ...|
| | | | | | |
Russia | 1,000| 0.1| 63,700| 5.1| ... | ...|
Spain | 219,100| 17.4| ... | ...|219,100| 17.5|
Sweden | 1,600| 0.1| 1,200| 0.1| ... | ...|
Switzerland | ... | ...| 6,400| 0.5| ... | ...|
Tunis | ... | ...| ... | ...| ... | ...|
Turkey-in-Asia | 15,300| 1.2| ... | ...| 15,300| 1.2|
United States | 425,100| 33.8| ... | ...| 10,800| 0.9|
Other countries | 2,600| 0.2| 34,100| 2.7| ... | ...|
-------------------+---------+-----+-------+-----+-------+-----+
World[135] |1,256,700|100.0|476,200| 37.8|441,600| 35.2|
-------------------+---------+-----+-------+-----+-------+-----+

-------------------+-------------------------------------------
| Recoverable lead in ores
| and pig lead
+---------------+-------------+-------------
| | |
| Consumption | Net imports | Net exports
+---------+-----+-------+-----+-------+-----
| | Per| | Per| | Per
| Net |cent.| Net |cent.| Net |cent.
Country | tons |[130]| tons |[130]| tons |[130]
-------------------+---------+-----+-------+-----+-------+-----
Algeria | ... | ...| ... | ...| 12,900| 1.3
Australia | 10,600| 0.8| ... | ...|233,900| 18.7
| | | | | |
Austria-Hungary | 39,100| 3.0| 15,300| 1.2| ... | ...
Belgium | 47,300| 3.7| 47,300| 3.8| ... | ...
Bolivia | ... | ...| ... | ...| 1,100| 0.1
Bulgaria | ... | ...| ... | ...| 2,200| 0.2
Canada | 25,200| 2.0| 6,400| 0.5| ... | ...
China | ... | ...| ... | ...| 14,000| 1.1
Egypt | ... | ...| ... | ...| 3,200| 0.2
France | 118,600| 9.1|109,000| 8.7| ... | ...
German S. W. Africa| ... | ...| ... | ...| 13,200| 1.0
Germany | 246,400| 19.1|167,100| 13.4| ... | ...
Great Britain | 211,000| 16.4|190,700| 15.2| ... | ...
Greece | ... | ...| ... | ...| 20,300| 1.6
Holland | 10,500| 0.8| 10,500| 0.1| ... | ...
India | | | | | |
(Burma) | ... | ...| ... | ...| 6,500| 0.5
| | | | | |
Italy | 35,900| 2.8| 11,000| 0.1| ... | ...
Japan | 20,400| 1.6| 17,000| 1.3| ... | ...
Mexico | ... | ...| ... | ...| 68,300| 5.5
Norway | 500| ...| 500| ...| ... | ...
Peru | ... | ...| ... | ...| 4,300| 0.3
Portugal | ... | ...| ... | ...| 600| ...
Rhodesia | ... | ...| ... | ...| 400| ...
| | | | | |
Russia | 64,800| 5.0| 61,700| 5.0| ... | ...
Spain | ... | ...| ... | ...|209,200| 16.7
Sweden | 2,800| 0.2| 700| ...| ... | ...
Switzerland | 6,400| 0.5| 6,400| 0.5| ... | ...
Tunis | ... | ...| ... | ...| 31,100| 2.5
Turkey-in-Asia | ... | ...| ... | ...| 15,300| 1.2
United States | 414,300| 32.1| 2,400| 0.2| ... | ...
Other countries | 36,700| 2.8| 36,700| 2.9| ... | ...
-------------------+---------+-----+-------+-----+-------+-----
World[135] |1,290,500|100.0|682,700| 52.9|636,500| 50.9
-------------------+---------+-----+-------+-----+-------+-----

[130] Percentages of World production of recoverable lead content of
ores.

[131] Percentages of World smelter production of pig lead.

[132] Percentage of mean of totals used in _a_ and _b_.

[133] Total recoverable lead content of ore production reported, less
lead content of Australian production in forms other than pig lead.

[134] Probably represents ore surplus rather than exports.

[135] Lack of proper balance in these totals shows error or
incompleteness, or lack of comparability, due in part to lag in the
statistics, which, however, show correctly the general situation.