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By W. Spencer Reid

ALTHOUGH there have been some developments during the last five years which have had far- reaching and important bearing on lead smelting, it cannot be said that any basic principles of pyrometal-lurgy have been discovered. Eighteen or twenty years ago the Dwight & Lloyd sintering machine was intro-duced and literally turned the roasting end of lead smelting upside down. There has been nothing com-parable to the advent of the sintering machine during recent years. Actual blast-furnace practice today is slightly, if any, better than it was five years ago ; although immeas-urably better than it was twenty to thirty years ago. Some tell us that as far as cleanness of slags is con-cerned, it is no better today than in the days of the old Romans. The metallurgist of a generation ago did very good work, considering the equipment he had available. It is true he was working with the cream of the ores, the clean oxides and carbonates and the low-zinc sul-fides. He was troubled very little with high zinc and selected his type of slag according to preference of -some authority such as Eilers, Iles, Raht, Hahn, etc. As these free-smelting ores were depleted the complex ores were encountered, and the metallurgist gradually discovered that he had to forget the old type slags and run a slag according to the percentage of zinc on the charge. I believe it is now universally agreed that SiO2 and CaO must be lowered and FeO raised in a slag as the ZnO increases. The ratio of these variations is practically uniform and can be relied upon over wide fluctuations of the determining element, zinc. These "bastard" slags, as they are sometimes inappropriately designated, are actually in daily use, and the metallurgist of today has been forced to adopt certain standards, as a guide to successful operation. These slags practically refute the old Eilers' theory that all good slags are chemical combinations of SiO2 with FeO and MnO, and CaO and MgO. Eilers' and the other type-slag theories were based upon the assumption that a good slag must con-form to a definite formula, such as 3 (FeO)2 SiO2 + 2 (CaO)2 SiO2 or 2 (FeO)2 SiO2 + 2 (CaO)2 SiO2 which respectively figure 31.3 and 36 per cent SiO2. The SiO2 was supposed to remain constant even with the entrance of impurities such as Zn and A1,0? into the slag. The increasing amount of impurities, espe-cially Zn, soon discredited the theory, for in actual practice the slag failed to run freely.

Jan 1, 1927

By B. L. Sackett

LEAD smelting has been an important industry in Utah for many years. The first lead smelting was done, over 60 years ago, at the Rollins mine in Beaver County, by burning heaps consisting of alternate layers of wood and high-grade carbonate ore. The lead thus obtained was. molded into bullets. With the development of. the mines, the problem of cheaper handling of the ore became important. The only outlet for this ore was Swansea or the Atlantic Coast but to ship to either cost $150 per ton or more for treatment and handling. From 1864 to 1871, experimenting was done with blast, Scotch hearth, and reverberatory furnaces, with the blast furnace surviving as, the standard plant. The first crude furnaces were circular or hexagonal in shape, and were made of adobe and stone, which quickly burned out. They were small, about 2 1/2 ft. in diameter, and smelted from 3 to 10 tons. in 24 hr. The metal had to be tapped from the bottom of the crucible, necessitating a shut down of the furnace during this process. This pro¬cedure caused salamanders to form around the tap hole when the furnace was started again, which frequently resulted in freezing. The campaign lasted until a tap of bullion was made. The first successful plant of the crude stone type was operated in 1870. From 1870 to 1872, there was a smelter building craze in the state. During that period, about 20 furnaces were built, chiefly near the mines, and their operation was limited and sporadic. The work was then placed in the hands of trained metallurgists, who standardized on the rectangular form of furnace. In 1871, Daggett, at the Winnamuck mine in Bingham, installed water-jackets around the smelting zone of the furnaces. These furnaces were circular; the diameter at the tuyere line was 3 ft. 6 in. and at the charge floor 5 ft. 3 in. The height from tuyere line to charge floor was 14 ft., height of tuyere line above top of crucible was 3 ft. 8 in. Fur-

Jan 8, 1925

By J. M. Rapkoch

In late October 1996, an acid plant at a major U.S. copper smelter was faced with unexpected and rapidly increasing pressure drop across the gas cooling tower in the acid plant, indicating a build-up on the packing. This threatened to halt operations if not resolved. Earlier that month, a smaller vessel in the acid plant was found to be completely plugged with lead sulfate. It was feared that a similar fate awaited the gas cooling tower unless the scale build-up was stopped. Although lead sulfate is present in most copper smelter acid plants, this accumulation was unusually severe. An investigation was launched to find the source of the lead, determine how lead is transported to the gas cooling tower, recommend operating practices to prevent such severe scaling, and seek ways to recycle the lead value in the scale covered polypropylene packing. Late in the investigation it was learned that the lead originated from an improperly executed recycling program.

Jan 1, 2000

By Jesús L. Valenzuela, José R. Parga, Salvador Aguayo, Héctor Moreno

The Merrill Crowe zinc-precipitation process has been applied worldwide on a large number of operations for the recovery of gold and silver resulting in a higher consumption of zinc dust from cyanide solutions. However, in some of plants this precipitate is of low quality, because lead, cadmium and especially copper are precipitated along with gold and silver. The low quality precipitate also requires more fluxes in smelting and shortens crucible life. In this study, a process is introduced to remove copper, silver, lead and cadmium from barren solutions following the Merrill-Crowe process. Copper and silver are removed by precipitation in a serpentine reactor, using sodium sulfide as the precipitator, and sulfuric acid for pH control. The recovery of lead and cadmium ions with natural hydroxyapatite using cow bone powder (CBP) as a new adsorbent material, is introduced. CBP is capable of removing lead and cadmium ions from aqueous cyanide solutions with 99% efficiency. It has the ability to compete with other existing commercial adsorbents for the removal of lead and cadmium. Results show that pH value has a significant effect on copper cyanide removal efficiency, and it was determined the optimal pH range to be 2 - 3. At this pH value, the copper cyanide removal efficiency achieved was up to 99 %; and for the cyanide associated with copper cyanide complexes, the recovery was 90%. Finally, the precipitate quality was improved 400% .This procedure was successfully run at three mines in México.

Jan 1, 2014

By H. V. Alminas

The U.S. Virgin Islands consist of three major islands (St. Thomas, St. John, and St. Croix) and some 50 smaller islands that are located primarily along the coasts of St. Thomas and St. John. St. Croix, the largest of the islands, is located approximately 160 km south-southeast of San Juan, Puerto Rico and is about 218 km in area (Fig. 1). St. Thomas, the second largest island is located 64 km east of Puerto Rico and incorporates approximately 77 km2. St. John is located immediately to the east of St. Thomas and incorporates approximately 49 km2. The climate in the U.S. Virgin Islands is maritime tropical. The average annual rainfall at higher elevations is 127-152 cm and at lower elevations 51-76 cm. There is no well-defined wet or dry season. Temperatures generally average in the 80's (F°) with only a 5°-7° F variation throughout the year.

Jan 1, 1987

By Morris J. Elsing

FOR MANY YEARS lead and zinc have had the so-called protection of a tariff and it is the purpose of the following brief discussion to show what' such protection actually accomplishes with a view to forecasting the possible results of the present copper tariff. In analyzing the subject, tabulations of the United States production, consumption, imports and exports, including ore and concentrates and all of the metallic products, of both lead and zinc have been made for each year since 1900. Of these data, the relationship of the imports and exports and the relative foreign and domestic prices are shown in Table 1. The conclusions drawn from these figures are listed below. 1. The United States is an exporter of zinc. 2. The United States is an importer of lead. 3. The average price of zinc at St. Louis for the last 32 years has been no higher than on the London market even though zinc and zinc ore have "enjoyed" a protective (?) tariff of varying amounts per pound for 22 years of this period. 4. The average price of lead on the New York market for 32 years has been 1.2c. per pound higher than on the London market, the tariff varying from 0.75 to 1.5c. per pound of lead in ore, and 1 to 2c. or more on manufactured lead.

Jan 1, 1932

By THOMAS LEONBRD WATSON

I. INTRODUCTION. THE results embodied in this paper are based on a careful field- and laboratory-study of the lead- and zinc-deposits of the Virginia-Tennessee district, begun in the latter part of the summer of 1904 and completed in the spring of 1905, preparatory to the publishing of a State report .on them. A separate description of the individual deposits in Virginia is purposely omitted, since I have already described them in considerable detail in a State report. The Tennessee deposits are described here in some detail for the reason that no detailed record of them has yet been published. Practically, this paper summarizes the results obtained from a study of the geology of the ore-deposits of the district as, a whole. (I had the pleasure of visiting the deposits of Virginia and Tennessee with Dr. H. Foster Bain of the U. S. Geological Survey, in April, 1905. Figs. 21 and 22 are from photographs taken by Dr., Bail.) II. HISTORICAL. . The first authentic records of lead-mining .in Virginia date hack more than 150 years; and the old lead-mines at Austinville, on New river in Wythe county, V a., were the first to be worked. Colonel Chiswell, a native of Wales, and one of the earlier adventurers in southwestern Virginia, was one of the first operators of the Austinville mines. Chiswell's operations at Austinville commenced in the year 1750, and closed shortly after the beginning of the Revolutionary War, in the' year 1776, covering a period of about 25 years. From that time to the present, mining has been carried on almost continuously in the Virginia area. For many years after the Virginia mines were operated, mining was confined exclusively to the lead-ores. The zinc-ores

Mar 1, 1906

By T. S. Bannos

Section 1417 of the Safe Drinking Water Act Amendments enacted by the O.S. Congress prohibits the use of lead containing solders for potable water systems in new construction or when making repairs. The legislature defines "lead-free" solder as containing less than 0.2% lead. In the development of a new solder it was recognized in addition to the lead free requirement, the alloy should perform as well as the popular 50/50 tin lead solder, both in application and properties. Another objective was to have only nontoxic elements. This led to the development of a 4.0% copper, 0.5% silver and 95.5% tin solder. Review of the merits of other alloy systems and the development of the physical properties along with test data are presented for the lead free tin. rich alloy.

Jan 1, 1990

By Wei Sun, Ruolin Wang, Wenjuan Sun, Junhao Fu, Haisheng Han, Zhao Wei

Pb–benzohydroxamic acid (BHA) (lead complexes of benzohydroxamic acid) exhibits high selectivity but low collecting efficiency in scheelite flotation. This paper reports the manner in which BHA and sodium dodecyl sulfate (SDS) were employed as ligands to coordinate with the lead ions to obtain a colloidal lead-group multiple ligand complex, i.e., the Pb–BHA–SDS, for improving the collecting efficiency of Pb–BHA. The flotation mechanism of Pb–BHA–SDS with respect to scheelite was investigated from the viewpoint of interface science based on the pure mineral flotation, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and contact angle measurements. The results showed that the BHA and SDS coordinated with Pb2+ to form novel leadgroup multiple ligand complexes, which are different from the traditional understanding associated with the mixed collectors. Pb–BHA–SDS was a better collector with stronger collecting ability and excellent selectivity in regard to a scheelite flotation than Pb–BHA. The addition of SDS to Pb–BHA enhanced the latter’s adsorption ability on the scheelite surface and improved the hydrophobicity of the collector’s nonpolar groups, rendering Pb–BHA–SDS as a more efficient collector at a low dosage. Keywords: Scheelite; Pb-BHA complexes; sodium dodecyl sulfate; multiple ligands; Pb–BHA–SDS

Jan 1, 2020

By W. J. O'CONNOR

THE production of lead in the United States for the period from 1720 to 1912 was 10,432,668 tons valued at $924,600,000. The average price during this period was 4.4c. a pound, although lead sold at times below 3 cents. We know that in the early days of lead smelting in Montana lead was deliberately lost in the slag and only enough reduced as bullion to collect the silver. This bullion was freighted by ox team to Corinne, Utah, the terminus of the railroad at that time, and shipped to Swansea or Omaha, Neb., for refining. The slag from some of the above mentioned operations contained as much as 15 per cent lead and has since been resmelted. Since 1921 the production of lead has increased each year and the price and tonnage have been as follows :

Jan 1, 1926

By R. G. Green, R. L. Dowdell

LEAD POISONING as a result of eating lead pellets deposited in marsh areas is a cause of high mortality among ducks, geese, and other waterfowl ingested lead shot become trapped in the gizzard with gravel and are slowly ground away by the grit. Absorption of lead as it passes through the intestine in a finely divided state produces severe lead poisoning which is usually fatal. Ducks and geese with lead poisoning develop first a typical green diarrhea. Later, paralysis of the wing muscles prevents flight. As the poisoning continues with further grinding of the shot trapped in the gizzard, increasing paralysis reduces the bird to helpless-

Jan 1, 1937

By J. J. Brown

Wilkes-Barre Meeting, Julie, runs., THE ore-hearth was the earliest type of furnace used in smelting Mississippi Valley lead-ores, which are very pure, and low in silver-content. The first smelters made no attempts to recover lead from the smoke; and since about 15 per cent. of the lead -in the charge escaped in this manner, early practice with the hearth was decidedly wasteful. At most of the large smelting-plants blast-furnaces with auxiliary roasters were substituted for the hearths long ago. But, upon the introduction of the Lewis and Bartlett bag-process for collecting fume, the ore-hearth was used by companies engaged in the manufacture -of pigments, simply on account of the large percentage of fume made by it. In fact, the extraction of lead was kept down by the use of hot blast and other devices. During recent years, however, several smelting companies have realized that the preliminary roasting of galena for the blast-furnace is not economical, and have, therefore, replaced the roasting-furnace with a modification. of the old Scotch hearth, in which a large percentage of the lead in a charge is recovered directly as pig-lead, while the remainder passes partly into fume and partly into slag low enough in sulphur to be charged into the blast-furnace without further treatment. The results obtained have proved so satisfactory, both As to recovery and operating-expense, that one eminent metallurgist has predicted the universal use of the ore-hearth on non-argentiferous ores. The-ore-hearth, thus employed as an adjunct to a blast-furnace plant, is rather a desulphurizer than a smelting-furnace proper,-the chief object being to make a blue slag suitable for the cupola-furnace. Hence, no special care is taken to obtain from it a large lead-extraction. * Head of Department of Ore Dressing and Metallurgy, Oklahoma School of Mines and Metallurgy, Wilburton, Okla.

May 1, 1911

By Hughes J. C

THE smelting plant consists of five large furnaces operating in the treatment of current flintered material, and one small furnace operating periodically in the treatment of copper dross and antimonial slag produced in the lead-refining process.he following table supplies the leading dimensions and details of the large furnaces:-(a) Crucible - Dimensions 17 ft. 2 in. long x 4 ft. wide x 2 ft. 3 in deep. Capacity - 30 tons lead. Class of lining - firebrick. No. firebricks required - 3000.(b) Crucible Tank - Dimensions 20 ft. 6in. long x 10 it. 6 in. Wide x 4 ft. 3 in. deep. Material - 1/2 in. mild steel.(0) Jackets - Dimensions 6 ft. long x 19 in. wide x 6in. thick. Material - Cast-iron. Average life - 2 years. Number per side - 11, with 13-in. bosh. Number per end - 3, with 9-in. bosh.

Jan 1, 1922

By T. S. Smith, C. C. Rennie

"THE LEAD-ZINC and tungsten mines of Canadian Exploration Ltd are on Iron Mountain, 8 miles south of Salmo, B.C., in the Nelson mining division. Relative location of the mines is shown on the general plan.First recorded lead production was in 1908 from surface outcrops. Small amounts of high lead ore were mined intermittently until 1926. No major lead-zinc production occurred until 1949 when outcroppings on the south side of the mountain were mined and diamond drilling began to prove the existence of a large replacement orebody. Lead-zinc ore has been mined continuously from the Jersey orebodies since March 1949, with monthly tonnage as high as 50,000 tons per month, but currently averaging 30,000 tons per month.Schee1ite-bearing tungsten ore was found in 1942 by H. Lakes in an old adit and open cuts at the north end of the Emerald tungsten orebody. The Emerald tungsten mine was developed by the Federal Government as a Wartime Metals project and operated for eight weeks in the fall of 1943, when the poor demand for tungsten closed the mine. Canadian Exploration Ltd. purchased the mine in 1947 and mined in excess of 100,000 tons in 1947-48 until the demand for tungsten dropped again and interest was centred on lead-zinc. The Federal Government repurchased and reopened the Emerald Mine in 195 L and built a new concentrator. The mine and mill were sold back to Canadian Exploration Ltd. in 1952.Regional Geology and IntrusivesThe host rock for both the lead-zinc and tungsten mineralization is the Laib formation of Lower Cambrian age, which consists of 400 feet of crystalline limestone underlain by beds of argillite, and argillaceous limestone locally altered to ""skarn"" or ""tactite"". The Laib limestone is overlain by black argillite and underlain by the Reno quartzite of Pre- cambrian age. Repetition of folded beds has allowed the interpretation of the large isoclinal fold which repeats the limestone (see general cross-section). Dolomitization and the associated lead-zinc ore have been found only in the right-side-up limestone and are not known in the overturned limestone.Two elongated stocks of granite cut the sediments. The Emerald stock outcrops along the east side of the Emerald tungsten mine and again west of the Jersey workings, while the Dodger stock outcrops only at the north end of the Iron Mountain. The shape and attitude of these bodies are believed to have been governed partly by pre-granite faulting and partly by pre-granite folding of the sediments. Although some forceful intrusion may have occurred the detailed granite surface indicates a gentle stoping emplacement."

Jan 1, 1949

By J. T. Fyles, C. G. Hewlett

"THE TOWN OF Salmo, rail centre for the Salmo lead-zinc mining district, is in southeastern British Columbia 26 miles by road east of Trail an about the same distance south of Nelson. The belt in which the mines occur is a few miles east of Salmo and extends about 6 miles north of the town and 17 miles south and southwest to the International Boundary. The belt includes the H. B. mine of The Consolidated Mining and Smelting Company of Canada, Limited, the Jersey mine of Canadian Exploration Limited, the Reeves MacDonald mine, and the Jack Pot property of New Jersey Zinc Explorations Limited.Since 1949, the Jersey and Reeves MacDonald mines have produced most of the lead and zinc in the district. From 1949 through 1954 these two mines together produced a total of 233,134 ounces of silver, 87,659,399 pounds of lead, 215,708,856 pounds of zinc and 475,397 pounds of cadmium. This amounts to more than 80 per cent of the total production of lead and 95 per cent of the total production of zinc from the district since the first recorded production in 1906. Reserves at the largest properties amount to several million tons of ore containing 4 to 7 per cent combined lead and zinc. Several prospects are potential producers.Regional StructureThe main structural units in the Salmo area are outlined in Figure I, and the major rock units of the stratigraphic column are listed in the following table. The lead and zinc deposits are replacements in a highly deformed limestone formation near the base of the Laib group, and all mineralized zones are on the south and east side of structural unit 2 (see Figure I)."

Jan 1, 1949

By Tanner A. C, Harraway D. H

Various circuits were tried at Mount Isa Mines during the period 1959 to 19G3 with the objective of improving the differential flotation of galena and sphalerite. Many benefits and disadvantages of the various circuits were revealed. An analysis' of ore characteristics and their effect on flotation was made -and resullted in the design of a proposed circuit which is currently in the process of installation.INTRODUCTIONSince 1936 when lead-zinc sulphide flotation commenced at Mount Isa, at least three types of ore have been encountered.Each ore has presented problems to flotation metallurgists.The three types of ore are,1. partially oxidized upper level sulphide ore,2. Black Star ore from the lower levels with its carbonaceous fraction, and3. Black Rock ore which is similar to 2, but more free milling.In retrospect a number of the metallurgical successes of the past were short lived. Often flowsheets or 0perating practices were designed to solve a single metallurgical problem associated with the current ore being treated. As the ore changed the problem would vanish and the method originally taken to counter the problem could become unnecessary or deleterious to the treatment of the new ore. The general lesson learnt from-the past-is-that thetreatment of Mount Isa lead-zinc ore involves a number of equally major problems...

Jan 1, 1963

Mount Isa Mines Limited has been mining silver-lead-zinc ore at Isa Mine for 60 years. Mining methods have evolved continuously, and current production rates of 4.7 Mt/yr are obtained from a combination of sublevel open stopping, cut and fill, and benching methods. In the near future, orebodies mineable by open stoping will be gradually depleted, and the relatively new benching method will be further refmed to replace cut and fill methods wherever possible.

Jan 1, 1993

By G. R. McMeekin

"THE TOPIC suggested for my contribution to this Symposium was ""Lead-Zinc Smelting - 40 Years of Pollution Control"". The history of the development of smelting industry at Trail and the control of sulphur dioxide could make quite an interesting historical study. However, in the field of environmental control, the public is not particularly interested in what you did yesterday, but rather what you are doing today and what you are planning to do tomorrow. I can't fault this approach, but because there are some subject lessons that history can demonstrate, I would like to tell enough of the story (under three headings) to bring a focus on matters of contemporary concern in regard to public relations and ecology. The three general headings suggested are: (1) time before the capture of by-product sulphur; (2) the capture of sulphur; and (3) the ecological and public relations conclusions from these."

Jan 1, 1972

By Haslam C. O, Taylor S

Four historical periods of Australian lead-zinc-silver exploration and development are identified.In the first period, 1841-1900, Australia's deeply weathered surface yielded bonanza deposits. The outcrops of easily worked secondary ores, enriched in silver and lead, were discovered by prospectors with the incentive of production at times of high silver price. Districts discovered in this period still contributed, in 1982, 60 per cent of Australia's lead-zinc production, mainly from Broken Hill.The second period 1901-1944, was one of strong mine development but stagnant lead-zinc-silver exploration. Mount Isa was discovered and developed, but otherwise effort was devoted mainly to the mining of deposit extensions and to the metallurgical flotation of zinc. The deposit discovery rate was low but the discovery of Mount Isa was so significant that discoveries of this period contributed, in 1982, 30 per cent of Australia's lead-zinc production.The third period 1945-1972 was one of re-invigorated exploration.New geological and geophysical surveys, developing concepts of ore genesis, and worldwide comparisons of orebody settings improved target area selection. Evolving remote sensing methods, and rapid analytical techniques, assisted detection of lead-zinc deposits. Initiation of exploration led to discovery:1. in regions of previously unsuspected lead-zinc-silver potential (Sorby Hills, Mons Cupri, Golden Grove).2. of poorly exposed deposits in recognized mineral districts (Hilton, H.Y.C., Woodlawn, Elura, Que River).3. during active exploration for another commodity (Brown's, Woodcutters, Mary River, Beltana, Lady Loretla and Pegmont).The period saw a sustained growth in lead-zinc-silver production mainly from established operations. Mines discovered during the third period contributed, in 1982, 7 per cent of Australia's lead-zinc production.In the fourth period from 1973 to the present, exploration initiatives became fewer but resulted in continued discovery of poorly exposed deposits at Teutonic Bore, Thalanga, Benambra, Scuddles, Hellyer, and Jillawarra. Development initiatives strengthened in the period and production commenced at Woodlawn, Teutonic Bore, Que River and Elura; pre-feasibility work commenced at Scuddles, Hilton, Lady Loretta and Thalanga.

Jan 1, 1984

Trial ore production began at the Hilton Mine in 1987 with ore being trucked into Mount Isa for treatment at the Lead/zinc Concentrator. The expansion of output from the Hilton mine required additional concentrator capacity which led to the design and construction of the Hilton Concentrator. Systematic laboratory and Pilot Plant testwork dating back to 1968 to develop a flowsheet and reagent regime suited to the varied and generally complex mineralogy of the Hilton ore was successfully concluded with a Pilot Plant trial using a sulphoxy based sphalerite depression system in early 1988.In May 1988, a decision was made to build a 750 000 t/y concentrator with some novel technological and capital-efficient features. The Hilton Concentrator commenced operations in December 1989 reaching target grinding rates and metallurgical performance by mid-1990. Current ore treatment rate is 800 000 t/y.Lead concentrates assaying 43 - 48 per cent Pb are combined with the Lead/Zinc Concentrator lead concentrates and smelted at Mount Isa. Zinc and Low Grade Middlings (LGM) concentrates are filtered in the zinc filter plant at Isa with those from the Lead/Zinc Concentrator and then railed to Townsville for export or treatment in Australia.

Jan 1, 1993