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Kansas Mineral Resources for Wartime Industries

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Aluminum from Kansas Clays

by E. D. Kinney and Norman Plummer

Summary—Clays of central and north-central Kansas constitute a vast potential reserve of low-grade aluminum ore. Millions of tons of clay having an alumina content ranging from 28 to 32 per cent could be mined economically by stripping methods: Smaller tonnages of clay ranging from 32 to 39 per cent alumina also are available. Several processes can be used to extract alumina from clays. A modified sulphuric acid process has been approved by Secretary Ickes for. the extraction from clay of aluminum for war industries.

European countries have been recovering aluminum from clay for several years. The processes used are well known and are theoretically sound. Clays have not been used as a source of aluminum in this country because of the fact that the metal can be recovered from bauxite (Al2O3·2H2O) at a lower cost. Kaolin, the clay richest in aluminum, has the composition Al2O3·2SiO2·2H2O. Bauxite contains 50 to 60 per cent alumina (Al2O3), whereas the maximum content of alumina in pure clay is 39.5 per cent. Bauxite contains 530 to 630 pounds of metal per ton of ore, whereas only 210 to 420 pounds of metal occur in a ton of raw high-grade clay. The supply of high-grade bauxite ore in the United States is sufficient for but a few years, and we now import about 50 per cent of our requirements from South America.

The consumption of aluminum has increased greatly in the past two years and will continue to do so. Aluminum is of vital importance in the production of war materials. Availability rather than cost will be of primary importance during the critical period of the war, but it seems reasonable to assume that, even without the necessities of a war economy, the vast deposits of clay in Kansas will come to be regarded as an important source of aluminum within the next few years. Clay has a far greater metallic content than that of many metallic ores now successfully treated.

Metallurgy of aluminum

There are two main steps in the recovery of aluminum from its ores: (1) the production of high purity alumina, and (2) the electrolytic reduction of alumina to aluminum. Aluminum-bearing minerals are dissolved from the ore either by the alkaline or the acid process and later converted to alumina. The alkaline process is the common method now used in treating bauxite. The acid method, while theoretically sound and suitable for treating clays, has not been used for commercial production in this country.

The first step in the process of recovery of aluminum from a clay ore consists of calcining the clay at a temperature of 500 to 600° C. to eliminate organic material and to increase the solubility of the alumina. In general, the alkaline process for the extraction of alumina from clays is not considered satisfactory because of the fact that the silica also is soluble. The alkaline process, however, has been successfully used by the Russians. A modification of this process is described by Kammermeyer and White (1940, pp. 683- 699). A mixture of clay, limestone, and soda ash is fired to clinker in a rotary kiln and subsequently leached with water. Extractions of 85 to 90 per cent of the total Al2O3 and Na2O in the clinker are possible.

Hydrochloric or sulphuric acid commonly is used in the acid extraction process. If hydrochloric acid is used, the calcined clay is decomposed by the acid at about 100° C.; aluminum chloride is removed by a hydrochloric gas current, leaving the iron chloride in solution. At 300° C. the aluminum chloride separates into alumina and hydrochloric acid; the latter is recovered and used again.

The United States Bureau of Mines has developed an improved sulphuric acid process. Secretary Ickes has proposed that a number of plants be constructed in which aluminum sulphate or alum could be produced from clay and other siliceous ores of aluminum. The alum, or other intermediate products, would be shipped to centrally located plants to be converted into aluminum.

The Kalunite process recently has been developed for extracting alumina from clay. This process has been described in a recent paper by Eicheberger (1941). The calcined clay is treated with sulphuric acid and potassium sulphate to form potash alum. The potash alum solution is autoclaved at 200° C. and 250 pounds per square inch pressure to give a basic potassium aluminum sulphate. This is heated to drive off the sulphur oxides, and the potassium sulphate is leached and removed in water solution for re-use. The residue is alumina, from which the metal, aluminum, is recovered by the well-known electrolytic process which also is used in extracting alumina from bauxite.

In the alkaline process a reasonably small amount of iron oxide in the ore is not objectionable, but silica causes trouble. Clay, being high in silica, generally is considered unsuitable for the alkaline process. Conversely, silica is not objectionable in the acid process whereas iron oxide gives trouble. Many Kansas clays are low in iron and could be treated by the acid process.

A very important factor in aluminum production is the cost of power. In general, manufacturers pay less than 3 mills per kilowatt hour for the 20,000 to 25,000 kilowatt hours needed to produce one ton of the metal. Kansas has an extremely large fuel reserve, available both for primary power and the generation of electricity. Although it may not be possible to produce power from this source for as little as 3 mills per kilowatt hours, it is possible that its use would be feasible in the war emergency. If this fuel reserve were used for power, the entire process of extracting the metal from clay could be carried out in Kansas. Either hydrochloric or sulphuric acid can be used in the extraction process. Kansas has a very large reserve of salt, which is used in the manufacture of hydrochloric acid, and a fairly adequate supply of sulphuric acid could be obtained from the pyrite which is washed out of Kansas coal.

The State Geological Survey of Kansas is undertaking research on methods of mechanical concentration of the alumina content of clay. Such mechanical processes, if developed on an economical basis, will not only improve the quality of fire clays but may become the first step in the production of aluminum from clay.

Kansas reserves of high-alumina clay

The high alumina clays of Kansas are discussed elsewhere in this bulletin in the section headed Clay, in which the age, origin, and ceramic properties and uses are discussed. The clays specifically described crop out in central and north-central Kansas, and in restricted areas in southwest Kansas. These clays differ from other Kansas clays which have been tested in that the dominant clay mineral is kaolinite. The principal mineral, other than kaolinite, found in these clays is finely divided quartz (SiO2). All proportions of silica and kaolinite are found in the material ranging from nearly pure silica to pure kaolin. At least half of the total tonnage available consists of clays of intermediate purity, in which class are included all clays having an alumina content ranging from 20 to 30 per cent. Millions of tons of clay having an alumina content of 28 to 30 per cent are readily available. The iron content ranges from 0.5 per cent to 1.8 per cent ferric oxide.

The largest deposit of this high-alumina clay exposed at the surface was found in an area in southern Cloud and northern Ottawa counties. Outcrops extending over an area about a quarter of a mile wide and more than two miles long were sampled. The beds are approximately horizontal, are fairly uniform in thickness, and are covered with an overburden of moderate thickness over a considerable portion of the area. The high-alumina part of this bed averages about 7 feet in thickness. A more siliceous, light-firing, refractory clay occurs below the high-alumina clay. The same bed of high-alumina clay was sampled also in Washington and Lincoln counties. Analyses of samples taken from this bed in three counties in Kansas are given in table 5.

Table 5—Analyses of a bed of high-alumina clay sampled in three counties. (Analyses by Raymond Thompson in laboratories of State Geological Survey of Kansas.)

Constituents Cloud County
(per cent)
Ottawa County
(per cent)
Washington County
(per cent)
SiO2 59.94 62.09 59.88
Al2O3 29.38 27.45 31.11
Fe2O3 1.20 0.58 1.69
CaO 1.10 0.94 0.24
Ignition loss 8.60 8.90 7.20
Total 100.32 99.96 100.12

When calcined, the above samples contain 32,01 per cent, 30.18 per cent, and 33.48 per cent alumina, respectively; this is based on the assumption that the ignition loss is due entirely to the loss of hygroscopic and chemically combined water in the clay.

Table 6—Representative analyses of north-central Kansas high-alumina clays. (Analyses by Raymond Thompson in laboratories of the State Geological Survey of Kansas; laboratory numbers of sample analyzed given at heads of columns).

Constituents El-12-4
(per cent)
(per cent)
(per cent)
(per cent)
SiO2 60.26 60.70 56.40 45.60
Al2O3 28.69 28.44 31.00 39.50
Fe2O3 0.49 2.88 1.08 0.67
CaO 0.21 0.27 0.18 0.16
Ignition loss 9.81 7.33 11.15 14.00
Total 99.46 99.62 99.81 99.93

The clays discussed above have not been developed commercially because prior to 1938 they were not known to exist, and because of the fact that their existence was not publicized until much later. Carload samples for plant trials have been shipped from four different deposits in the outcrop area. The experience gained from removing the carload lots has demonstrated that the clay can be easily mined and that the quality is uniform, at least within the limits of the small tonnage taken out.

No facilities have been set up for loading the clay from any of the deposits directly onto railroad cars. In most cases, the better deposits of clay are a few miles from the nearest railroad siding. Clay from some of the larger deposits, however, can be trucked over all-weather roads to the sidings.


Eichelberger, F., 1941, Aluminum from western alunites: Min. Congo Jour., vol. 27, no. 11, pp. 37-39.

Kammermeyer, K., and White, A. H., 1940, Extraction of alumina from kaolin and other silicates: Am. Inst. Chern. Eng., Trans., vol. 36, no. 1166, pp. 683- 699.

Sasse, G., 1937, Producing aluminum from clays: Ceramic Age, vol. 30, no. 2, p.46-47.


by E. D. Kinney

Summary—Although iron is not now produced in Kansas, there are two potential sources for small-scale production.

Iron from mine waters

Kansas has a potential source of iron, now unused, in the mine waters of the lead and zinc area in Cherokee County. Practical methods of removing objectionable acid and iron from mine waters discharged from lead and zinc mines in Cherokee County have been described (Kinney, 1941). Kinney's studies show that mine waters in the Baxter Springs area contain as much as 6,000 parts per million of iron and that several tons of iron hydroxide are deposited daily in settling ponds and in river channels. According to Kinney, a plant treating daily 5,000,000 gallons of mine water containing 1,000 parts per million of iron would produce in one year the equivalent of 10,845 tons of Fe2O3, if operating at 100 per cent efficiency.

Manufacturers of Portland cement are finding it necessary to add iron to the common raw materials in order to produce a certain kind of cement used in mass concrete work. At present, pyrite cinder is being shipped from St. Louis to Kansas cement mills; iron hydroxide from mine waters could be substituted. Other uses for iron recovered from mine water will be found, and it should be remembered that mine operators have lowered production because of their reluctance to discharge additional untreated waters into surface drainage channels. Thus, it seems that treating plants are necessary to bring about the desired increase in lead and zinc production and that economic use of the recovered iron is highly desirable to offset the cost of treating the mine waters.

Iron from hematite and limonite

Hematite and limonite, which are commercial iron ores at various places in the United States, occur in Kansas, although no large deposits are known and no ore is mined. Hematite is iron sesquioxide (Fe2O3), containing 70 per cent iron. Limonite is the hydrous sesquioxide of iron (2Fe2O3·3H2O); it contains 59.8 per cent iron. Possibly the best known prospect is in the SE sec. 13, T. 13 S., R. 11 W., Russell County. Here a bed of hematite and limonite eight feet thick crops out in the top of the Dakota formation of Cretaceous age. This potential ore is of sedimentary origin and is stratified. It is somewhat contaminated by thin interbedded layers of sandstone parallel to the stratification, although in places individual layers of iron oxide as thick as ten inches free of sandstone can be observed. Deposits of this kind might furnish iron ore for chemical purposes, such as for the cement industry.


Kinney, E. D., 1941, Treatment of mine waters as a factor in the mineral production in southeastern Kansas: Kansas Geol. Survey, Bull. 28, pt. 1, pp. 1-16.

Plummer, Norman, and Romary, John, 1942, Stratigraphy of the pre-Greenhorn-Cretaceous rocks of north-central Kansas: Kansas Geol. Survey, Bull. (in preparation) [available online]


by J. C. Frye and J. M. Jewett

Summary—Magnesium-bearing oil field brines and beds of rock dolomite in Kansas constitute important potential sources for production of the metal, magnesium.

Attention is here directed to the strategic importance of the metal, magnesium, and to the fact that magnesium is present in large quantities in deep ground waters in Kansas and in certain rock dolomites in the state.

Magnesium is a silvery white metal of great strength. It is the lightest of all the known metals that are comparatively little altered under ordinary atmospheric conditions. Its specific gravity is 1.74. The specific gravity of aluminum is 2.7. Copper is more than 5 times as heavy as magnesium. Magnesium does not occur in native form; that is, it is not found naturally in the uncombined, or metallic, state. It is, however, one of the most abundant of metals. It is a part of many rocks, and its compounds are present in many natural waters. Ordinary sea water contains more than 0.1 per cent. magnesium, and the magnesium content of many "mineral waters" is much higher.

Magnesium is produced from natural and artificial magnesium chloride (MgCl2) by electrolysis. It also is obtained from the calcined form of magnesite (MgCO3) and recently from rock dolomite, the only common ores of magnesium. Calcined magnesite (MgO) is reduced with coal in electric furnaces. The temperature employed is high enough to volatilize the magnesium, which is later condensed. In the United States, magnesium is being produced from brines obtained from wells in Michigan and from ocean water at Freeport, Texas. It is reported that the Texas plant uses 500,000,000 gallons of water and produces annually 7500 tons of metallic magnesium. In the process of extracting magnesium from natural brines the magnesium-bearing water is treated with slaked lime to produce magnesium hydroxide. The magnesium hydroxide is treated in turn with hydrochloric acid to produce magnesium chloride. An artificial magnesium chloride thus is made available for the electrolysis process.

It has been suggested that in Kansas it might be advisable to use slaked dolomite instead of chalk and thus produce magnesium hydroxide simultaneously from the brine and from the dolomite. This would be particularly advantageous in the south-central area where the dolomite deposits are nearer the oil fields than are chalk or limestone deposits.

Recently, several magnesium plants utilizing different processes have been constructed in Nevada and California. In some of these plants dolomite is being used as a source of magnesium.

Uses of magnesium

Magnesium is used as a deoxidizing and desulphurizing agent in the manufacture of metals and alloys. Until recently, this perhaps was its greatest use. It now is used extensively in making castings. Magnesium castings as aircraft parts include crank cases, pistons, oil pans, bearings, and control levers. Magnesium castings are used also as parts in surveying instruments, motion picture machines, field glasses, microscopes, and in many other instruments. Magnesium is made into sheets, rods, and tubing, which have a multitude of uses wherever material of light weight and great strength is desired. The usefulness of magnesium in aircraft construction is extremely significant at the present time.

Several magnesium alloys now are being produced. Magnesium and aluminum alloys are especially useful in the manufacture of airplane parts. In some of these alloys as little as 0.5 per cent magnesium is used. It is reported that an alloy containing 93 per cent magnesium, 7 per cent aluminum, and 0.04 per cent manganese has a tensile strength of 30,000 pounds per square inch. Magnesium is combined with beryllium to produce one of the lightest known alloys, and is combined with lead to give a much harder product than lead alone.

Magnesium is used in making tracer bullets, tracer shells and incendiary bombs, and in making flash-light powders, photographic flares and other articles useful and essential in modern warfare and industry.

It has been suggested that several small plants for the partial completion of the magnesium extraction process might be set up in Kansas and in other Mid-Continent states. Such small plants would concentrate from the brines either magnesium hydroxide, Mg(OH)2 which contains 834 pounds of magnesium per ton, or magnesium chloride, MgCl2, which contains 510 pounds of magnesium per ton. These concentrates would then be shipped to a centrally located plant at a place where cheap electricity is available for the final extraction of metallic magnesium.

The possible extraction of magnesium from oil-field brines is of especial interest because it may be a means of converting into a valuable mineral resource a by-product of the petroleum industry that heretofore has been regarded only as deleterious waste.

Magnesium from Kansas Oil Field Brines

Reconnaissance studies of available data pertaining to Kansas oil field brines have shown that over a wide area there are natural brines having magnesium content several times that of ordinary ocean water. Official water sample analyses made by the Kansas State Board of Health have provided much of the data used in these studies. Table 7 shows in parts per million the magnesium content of a selected group of water samples. These analyses were selected from the files of the Board of Health and from other sources because of their high magnesium content, and it should be stated that because of the limited number of samples available this table probably does not list all Kansas counties in which brines of high magnesium content can be obtained. From several hundred analyses those showing a magnesium content of 3,000 parts per million, or about 25 pounds of magnesium per 1,000 gallons of liquid, or more were selected and included in the table. A large number of deep brines in Kansas have a magnesium content as high, or generally higher, than that of ocean water (about 1,400 parts per million, or less than 12 pounds of metal per 1,000 gallons of liquid).

Table 7—Magnesium content of selected Kansas oil field brines, as sampled from disposal systems.

Name of
County Formation,
source of
Total solids,
parts per
parts per
Bloomer Barton Topeka ls. 193,000 3,400
Burrton Reno "Chat" 108,000 1,700
Burrton Reno Hunton ls. 72,000 1,150
Burrton Reno Arbuckle ls. 66,000 935
Caldwell Sumner Wilcox fm. 223,000 2,400
Cunningham Kingman KansasCity ls. 224,000 3,700
Rainbow Bend Cowley Kansas City ls. 225,000 3,500
Bartlesville ss. 229,000 2,300
Layton ss. 217,000 3,300
Hoover ss. 200,000 2,800
225,000 3,700
Ritz-Canton McPherson "Chat" 103,000 2,000
Sullivan Russell Arbuckle ls.   2,700
Valley Center Sedgwick Kansas City ls. 211,000 3,500
Mississippi ls. 100,000 1,200
Voshell McPherson Hunton fm. 74,000 1,700
Wilcox fm. 38,000 580
Arbuckle ls. 43,000 634

Table 7, above, shows the magnesium content of selected water samples from different stratigraphic units in individual wells in different locations in Kansas. Table 8 shows the average magnesium content of water from various formations in several Kansas oil fields.

Table 8—Magnesium content of selected Kansas deep brines, as pumped from oil wells.

County Name of well,
lease, or field
Sec. Township Range Formation,
source of water
in feet
parts per
Butler Miner No. 6 9 29S 4E     3920
Cowley Udall field 28 30S 5E     3130
Shafer field 15 31S 3E     3220
Clark field 6 31S 4E Composite brine   3620
Texas-Little lease 21 31S 4E Composite brine   3050
Shafer field 19 32S 3E     4540
Waite No. 1B 12 32S 4E "Oswego lime"   4020
Graham field 10 33S 3E     3510
Ellis Fairport field 36 12S 16W "Oswego lime" 2975 3125
Phillips-Schneider No. 2 18 12S 17W Kansas City ls.   3115
Ellsworth   7 17S 10W Kansas City ls. 3100 3750
McPherson Ritz-Canton field 9 19S 2W Kansas City ls. 2435 3950
Reno Abbyville field 24 24S 8W Kansas City ls. 3500 3560
Rice Porter-Dierdorf No. 1   18S 7W   1400 4470
1925 3820
2590 3590
Porter-Dierdorf No. 1   18S 7W   2740 3550
Cambell No. 1   18S 8W   1400 5040
2600 3750
2715 3310
2855 3730
2920 3310
Brandenstein field 11 19S 10W Kansas City ls.   4030
Raymond field 21 20S 10W Lansing ls. 3130 3726
Arbuckle fm. 3330  
Kansas City ls. 3200 3830
Russell Central-Benso No. 1B 4 14S 15W "Oswald lime" 3027 4260
Signal-Taylor No. 1 26 15S 13W     3000
Sedgewick Continental-Casey No. 2 16 25S 1E     4160
Jacobs No. 2 22 25S 1E     4500
Valley Center field 7 26S 1E     4290
Phillips Willhite No. 1 27 26S 1E     3500

Large volumes of brine are included in the wastes brought to the surface in Kansas oil fields, and the problems of disposal of oil-field brines have received much attention. Until recently, the general method of brine disposal has been impounding on the lease. At the present time, large volumes of brines are returned to the subsurface formations through disposal wells. Some brines are used in water flood operations as a means of secondary recovery of oil.

Figures expressing the exact volume of brine produced in various Kansas oil fields are not easily obtained, but estimates believed to be fairly accurate can be made. It is believed that in general the ratio of water to oil in the fluids being pumped in Kansas is about 2 to 1. Some fields are producing 85 to 90 per cent water and 10 to 15 per cent oil. In several of the major fields disposal wells are in operation that have a daily capacity of 30,000 to 50,000 barrels of water. If the brine disposed of in such wells has a magnesium content of 4,000 parts per million, then about 40,000 pounds of magnesium are disposed of daily. The concensus of opinion is that in some of the larger oil pools in Kansas producing from the Arbuckle or "siliceous lime" the volume of brine that can be produced is limited only by the available pumping equipment. Water from other stratigraphic formations is not so abundant. More than 6,863,100 barrels of water having a magnesium content of 3199 parts per million have passed through a single disposal system in the Burrton field, Reno County, in the past five year.

Because of the fact that brines of high magnesium content are produced in the oil fields, it seems reasonable to suggest that the possibility of practical magnesium recovery from oil-field brines should be carefully considered. Additional samples of Kansas brines are now being collected for analysis in the chemistry laboratories at the University of Kansas. In some cases it may be found feasible to treat water passing through disposal systems for magnesium extraction. It may even be practical to pump brine from abandoned wells or from wells drilled especially for brine production. It should be noted that not all brines with high magnesium content are associated with oil fields. Analysis of brine from a well drilled many years ago at Lawrence, Douglas County, showed 6,309 parts per million of magnesium, or more than 50 pounds of magnesium per 1,000 gallons of brine (Bailey, 1902, p. 151). The Lawrence well was drilled to a depth of 1,400 feet; the depth from which the brine was produced is unknown. It is reported that the well flowed for several years before being filled.

Magnesium from Dolomite

Rock dolomite in the Permian rocks in central and southern Kansas constitutes another potential magnesium ore. The mineral dolomite, which is the dominant constituent of rock dolomite, is the carbonate of magnesium and calcium; its chemical formula is CaMg(CO3)2, and the theoretical composition is carbon dioxide (CO2) 47.8 per cent, calcium oxide (CaO) 30.4 per cent and magnesium oxide (MgO) 21.7 per cent. Varieties of rock dolomite occur in which the proportion of calcia to magnesia deviates from this proportion because of the presence of calcite (calcium carbonate) or other substances.

Dolomite in Kansas

Dolomite occurs in the surface rocks of Kansas in two formations. One is the Stone Corral dolomite that crops out in Rice, Reno, Kingman and Harper counties. This deposit is about 6 feet thick in Rice County but is somewhat thinner farther south. In the subsurface some distance from the outcrop this rock is an aggregate of dolomite and anhydrite crystals, but in the shallow subsurface and in surface exposures the anhydrite portion has been removed by action of ground water. This has rendered the rock somewhat cellular, and because anhydrite has been in part replaced by calcite, the relative proportion of the latter has been somewhat increased.

The thickest surface expression of the Stone Corral dolomite is in T. 20 S., R. 6 W., eastern Rice County. There the rock is well situated for convenient stripping operations. It is estimated that a single strip pit, from which it would be necessary to remove only a few feet of overburden, could be developed over at least one-half of one square mile. There are other favorable stripping localities, especially in Reno and Kingman counties.

The Day Creek dolomite is a thinner deposit, being about 2 1/2 feet in thickness. There are excellent outcrops in the vicinity of Ashland, Clark County. These outcrops are not so favorably located for large-scale strip mining, but it is estimated that at least a million tons could be mined easily with the removal of a comparatively small volume of overburden.

Locations of outcrops of both formations are shown in figure 12. The eastern band of outcrops is the Stone Corral dolomite and the western area is the Day Creek dolomite.

Chemical analyses of samples from both of the above-described dolomite formations are presented in tables 9 and 10, below.

Table 9—Chemical analysis of sample of Day Creek dolomite, T. 32 S., R. 23 W., Clark County.

Constituents Per Cent
SiO2 1.64
Al2O3 1.28
Fe2O3 1.98
CaO 31.54
MgO 18.02
Loss on ignition 46.34
Total 100.80
CaCO3, calculated 56.14
MgCO3, calculated 37.66

Table 10—Chemical analyses of five samples (1-5) of Stone Corral dolomite, from T. 20 S., R. 6 W., eastern Rice County

Constituents Per Cent
(1) (2) (3) (4) (5)
SiO2 3.04 2.48 2.52 4.26 2.68
Al2O3 1.43 2.61 2.89 5.34 2.54
Fe2O3 0.53 0.35 0.35 0.98 0.54
CaO 36.22 35.92 36.44 29.66 33.82
MgO 14.40 14.08 13.52 16.33 15.35
Loss on ignition 41.40 43.46 43.29 41.02 43.25
Total 97.02 98.90 99.01 97.59 98.18
CaCO3, estimated 64.70 64.02 65.00 52.92 60.35
MgCO3, estimated 30.10 29.43 28.24 34.10 32.09

Because of the urgent need for magnesium it is believed that Kansas dolomites should be thoroughly investigated as a potential magnesium ore.

Kansas reserves

Conservative estimates indicate that at least 15,000,000 tons of rock dolomite can be mined easily by stripping methods from the Stone Corral deposit, and that 1,000,000 tons can be obtained in the same way from the Day Creek bed. The magnesium content of one ton of ore that contains 20 per cent magnesium oxide is about 240 pounds. It has been suggested that the "chat" piles of southeastern Kansas might constitute a possible source of magnesium. Although there is some dolomite in the "chat", the presence of a considerable amount of chert and limestone probably would make the material unsuitable for such development.

Age and origin

The two dolomites described above are of Permian age and are the result of deposition from marine waters in what probably was an enclosed marine basin.


Bailey, E. H. S., 1902, Special report on mineral waters: Kansas Univ. Geol. Survey, vol. 7, pp. 1-343, frontispiece, pls. 1-22. [available online]

Norton, G. H., 1939, Permian red beds of Kansas: Am. Assoc. Petroleum Geologists, Bull. 23, pp. 1751-1819, figs. 1-24.

Schmidt, Ludwig, and Wilhelm, C. J., 1938, Disposal of petroleum wastes on oil-producing properties (with a chapter on soils and water resources of Kansas oil areas, by Ogden S. Jones): U.S. Bur. Mines, Rept. of Investigations 3394, pp. 1-25.

Taylor, S. S., Wilhelm, C. J., and Holliman, W. C., 1939, Typical oil-field brine-conditioning systems; preparing brine for subsurface injection: U.S. Bur. Mines, Rept. of Investigations 3434, pp. 1-71, figs. 1-15, tables 1-19.

Wilhelm, C. J., Thorne, H. M., and Pryor, M. F., 1936, Disposal of oil-field brines in the Arkansas river drainage area in western Kansas: U.S. Bur. Mines, Rept. of Investigations 3318, pp. 1-28, figs. 1-3, tables 1-11.


by E. D. Kinney

Summary—Pyrite is used chiefly in making sulphuric acid. The Kansas reserves are related to coal reserves and production inasmuch as Kansas pyrite is a by-product of the purification of coal.


Pyrite or iron pyrites is an opaque, brittle, pale brass-yellow metallic mineral consisting of iron and sulfur (FeS2). Because of its color, it commonly is called fool's gold. Pyrite commonly crystallizes in the form of cubes or pyritohedrons. It occurs also in massive, fine granular and sometimes in nodular, stalactitic, or subfibrous radiated forms. When struck on steel, pyrite gives off sparks. The mineral is hard (6.0 to 6.5) and has a specific gravity of 4.9 to 5.1. It breaks with a conchoidal or uneven fracture, Pyrite occurs in rocks of all ages, mainly associated with coal-bearing deposits and in veins, but also in clay and shale and argillaceous sandstones.

Kansas pyrite is produced solely as a by-product of the purification of coal. Impurities in the coal, amounting to about 3 per cent and consisting largely of shale and pyrite, are removed in the purification process. A process of classification is employed which uses settling cones with a heavier than water medium; coal floats and the impurities sink in the medium. From the impure portion, pyrite is recovered in another concentrating process. The recovery of pyrite is approximately 10 pounds per ton of coal.


Kansas pyrite is sent to a chemical plant in St. Louis, where it is converted into sulfuric acid.


The reserves of pyrite are intimately related to the reserves and production of coal, which are discussed elsewhere in this report.

Zinc and Lead

by E. D. Kinney and R. M. Dreyer

Summary—During 1940, Kansas produced about 57,000 short tons of zinc and about 12,000 short tons of lead. The known reserves are small but may be extended by recent exploration studies of the State Geological Survey.

Location of deposits

The zinc and lead ore deposits of Kansas are part of those of the Tri-State district of southeastern Kansas, northeastern Oklahoma, and southwestern Missouri. Zinc and lead mining in Kansas is confined to the southeastern comer of Cherokee County, comprising the Kansas portion of the district.

Character and occurrence of ore

The ore in the Tri-State district occurs in definite stratigraphic horizons in the Mississippian limestones; these horizons in general lie 100 to 200 feet below the contact with the overlying Cherokee shale. Unconformably overlying the Mississippian limestone in the greater part of the Kansas area of the mining district is a cover of barren Cherokee shales and interstratified sandstones, which reach a maximum thickness of about 250 feet in the Kansas portion of the district. Inasmuch as the Mississippian and Pennsylvanian rocks dip gently northwestward, the ore is found at progressively greater depths toward the west. The depth to ore in the Kansas portion of the field varies from about 150 to 400 feet. The ore tends to be concentrated in portions of the district which have been subjected to intense fracturing and brecciation.

The principal ore mineral is sphalerite (zinc sulphide). In certain parts of the field there also are considerable amounts of galena (lead sulphide). Associated with these two ore minerals in some places are the iron disulphides, pyrite and marcasite. The ore also contains minor amounts of greenockite (cadmium sulphide) and chalcopyrite (copper iron sulphide). Generally, the sulphide mineralization is associated with intense chertification. Dolomitization likewise is found in some places. Sphalerite, the principal ore mineral, commonly is brown to black in color, has a resinous luster, a hardness of about 4.0 and a specific of 3.9 to 4.1. Galena, the lead ore mineral, commonly is found in steel-gray cubes having cubic cleavage and a specific gravity of 7.4 to 7.6. The ore bodies are very irregular in shape. In the past, the outlines of the ore bodies have been delineated by intensive churn-drilling programs. Generally, the individual bodies have relatively large horizontal dimensions.

Lead and zinc production

The Tri-State district is the largest zinc-producing district and the third largest lead-producing district in the United States. In 1940, the mine production of zinc in the Tri-State district was 232,437 short tons, or 35.0 per cent of the total United States mine production and 14.2 per cent of the total world's smelter production. Of the total Tri-State production, 24.5 per cent comes from Kansas.

In 1940, the mine production of lead in the Tri-State district was 35,311 short tons or 7.7 per cent of the total United States mine production and 2.6 per cent of the total world smelter production. Of the total Tri-State production, 33.8 per cent comes from Kansas. Tables 11 and 12 present a statistical summary of Kansas zinc and lead production for the past five years.

Table 11—Kansas zinc production. [Minerals Yearbook, U.S. Bureau of Mines, 1940.] (Mine production in short tons.)

Year Kansas Tri-State
% of Tri-State
production coming
from Kansas
Total U.S.
% of U.S.
production coming
from Kansas
World smelter
(metric tons)
1936 79,017 226,857 34.83 575,574 13.73 1,464,000
1937 80,300 236,585 33.94 626,362 12.82 1,626,000
1938 73,024 196,174 37.22 516,703 14.13 1,568,000
1939 68,971 224,446 30.73 583,807 11.81 1,635,000
1940 57,032 232,437 24.54 665,068 8.58 Not avail.

Table 12—Kansas lead production. [Minerals Yearbook, U.S. Bureau of Mines, 1940.] (Mine production in short tons.)

Year Kansas Tri-State
% of Tri-State
production coming
from Kansas
Total U.S.
% of U.S.
production coming
from Kansas
World smelter
(metric tons)
1936 11,409 38,842 29.37 372,919 3.06 1,478,000
1937 16,008 50,274 31.84 464,892 3.44 1,679,000
1938 15,239 39,400 38.68 369,726 4.12 1,704,000
1939 13,697 44,176 31.01 413,979 3.31 1,741,000
1940 11,927 35,311 33.78 457,392 2.61 Not avail.

Ore dressing

After mining, the first treatment is milling to produce zinc and lead concentrates carrying 60 and 75 per cent of the metals respectively. The waste part of the ore, mostly chert, is rejected and forms the "tailing" or "chat" piles common in the district. The milling process consists of crushing the ore until the mineral grains are released, followed by gravity concentration, flotation concentration, or both. In gravity concentration the heavy zinc and lead minerals separate to the bottom of the concentrating device. In the flotation process certain minerals, usually those of metallic luster, such as zinc and lead sulphides, cling to air bubbles, if the.ore is finely ground and agitated in water and air. The affinity of "flotable" minerals for air bubbles is increased by the addition of small amounts of oil and chemicals. The floated minerals rise to the top of the agitated mixture and are recovered in a froth. The waste part of the ore settles and is run to waste. The method of milling has changed much in recent years. Instead of having a large number of small concentrators, much of the ore is sent to large central mills that handle the ore from many mines. The largest of these mills, located in Oklahoma near Picher, has a daily capacity of at least 10,000 tons of ore. Here a new ore concentrating process employing a differential density cone, known as the "sink and float" or Wuensch process, has replaced older machines. Instead of using water as in jigging, an emulsion of finely divided lead sulphide and water is employed. The density of the medium is such that heavy mineral particles settle, while the waste part of the ore is carried away.

Smelting Kansas zinc and lead ore

Zinc can be produced either by the retort or the electrolytic process. The former process accounts for 75 per cent of the zinc smelted in the United States. Practically all Kansas ore is treated by the retort process. Formerly, Kansas had its own zinc smelters. With the depletion of favorably situated gas fields and as a result of unfavorable freight rates, zinc smelting in the state ceased. The ore is smelted in Oklahoma, Arkansas, or the eastern states.

The smelting of zinc ore is somewhat complicated. As received at the smelter, the zinc sulphide concentrate contains about 60 per cent zinc. It is roasted to drive off sulphur, used in making sulphuric acid. The sulphide thus is converted to the oxide. The oxidized ore, mixed with an excess of coal, then is placed in a fire-clay retort, heated to white heat, and reduced to zinc. A peculiarity of the process is that the zinc, at the high temperature of reduction, is in the form of vapor. The vapor passes to a condenser attached to the retort, condenses to liquid, is ladled and cast. The smelting is accomplished in long narrow furnaces fired by natural gas. Some 250 retorts are arranged in rows on either side of the furnace with condensers protruding through the side walls. The metal produced, called "spelter", carries 98 per cent zinc.

The smelting of lead ore is relatively simple. Much of the Kansas lead concentrate is treated at Galena, Kansas, where the usual process of reduction smelting is followed. The 70 per cent lead concentrate is roasted to remove sulphur and then charged into a blast furnace together with limestone flux and coke. Blast furnaces produce metallic lead. Lead produced in the Mississippi Valley region is quite pure and requires no important refining operation. After tapping, and with little further treatment, it is ready for market.

Uses for zinc and lead

The principal uses of zinc are in galvanizing and brass making. Large amounts of zinc also are used in die casting, battery cans, and photoengraving. Zinc salts are widely used as high-grade pigments. Because of its use in brass, galvanizing and die castings, zinc has become a strategic metal in the national rearmament program. Lead and lead alloys are used in storage batteries, cable coverings, ammunition, solder, foil, bearing metal, and type metal. Lead salts are widely used as pigments.

Ore reserves and future production

The high-grade ore reserves of the Tri-State district are being rapidly exhausted. Reserves of low-grade ore are known, and it is possible that some of these submarginal ores could be mined if the government sees fit to grant sufficient subsidies. Inasmuch as the Tri-State district constitutes the principal source of zinc in the United States, it is important that attempts be made to locate new high-grade ore reserves. It is generally recognized that possibilities for new ore discoveries are better in the Kansas portion of the field than elsewhere. For this reason, the State Geological Survey of Kansas recently has made intensive efforts to develop new methods of exploration which could be used by the ore producers in their search for ore. During the summer of 1941 the State Geological Survey, working in cooperation with the University of Kansas Engineering Experiment Station and with the Tri-State Zinc and Lead Ore Producers' Association, began a comprehensive program of geophysical investigations in the Tri-State area. The purpose of these investigations was to develop some geophysical method or combination of methods which could be used to guide the drilling programs. It was hoped that the application of geophysical methods would serve not only to reduce the total cost of ore exploration in the district, but also would serve considerably to accelerate exploration as well as to aid in the finding of new ore bodies which normally might not be found in the course of the churn-drilling program. The first phase of the geophysical work has been completed and has indicated that geophysical methods of exploration can be successfully used to map structures associated with ore mineralization. Such geophysical methods are now in a stage in which they can be used successfully to guide exploration in the Tri-State district.


Bastin, E. S., et, al., 1939, Contributions to knowledge of the lead and zinc deposits of the Mississippi Valley region: Geol. Soc. America, Special Paper 24, pp. 1-156, figs. 1-27, pls. 1-4, tables 1-4.

Fowler, G. M., and Lyden, J. P., 1932, The ore deposits of the Tri-State district: Am. Inst. Min. Metall. Eng., Trans., vol, 102, pp. 206-251.

Fowler, G. M., and Lyden, J. P., 1934, Sequence of structural deformation in the Oklahoma mining field: Min. Metall., vol. 15, pp. 415-418.

Fowler, G. M., Lyden, J. P., Gregory, F. E., and Agar, W. M., 1935, Chertification in the Tri-State mining district (with discussions): Am. Inst. Min. Metall. Eng., Trans., vol, 115, pp. 106-163.

Hofman, H. O., 1922, Metallurgy of zinc and cadmium: McGraw-Hill Book Co., New York, pp. 1-341, figs. 1-261, tables 1-51.

Kinney, E. D., 1941, Treatment of mine water as a factor in the mineral production of southeastern Kansas: Kansas Geol. Survey, Bull. 38, pt. 1, pp. 1-16, figs. 1-3. [available online]

Landes, K. K., 1937, Mineral resources of Kansas counties: Kansas Geol. Survey, Mineral Resources Circ, 6, pp. 1-110, unnumbered figures. [available online]

Pierce, W. G., and Courtier, W. H., 1937, Geology and coal resources of the southeastern Kansas coal fieid: Kansas Geol. Survey, Bull. 24, pp. 1-122, figs. 1-13, pis. 1-12; [available online]

Siebenthal, C. E., 1915, Origin of the zinc and lead deposits of the Joplin region, Missouri, Kansas, and Oklahoma: U.S. Geol. Survey, Bull. 606, pp. 1- 283. [available online]

Weidman, Samuel, 1932, Miami-Picher Tri-State district: Univ, Oklahoma Press, Norman, pp. 1-177, figs. 1-12, pls, 1-11, tables 1-26.

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Kansas Geological Survey, Geology
Placed on web Nov. 2, 2017; originally published May 9, 1942.
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