Circular 604

Mines in the Illinois Portion of the Illinois-Kentucky Fluorspar District

F. Brett Denny,¹ W. John Nelson,¹ Jeremy R. Breeden,¹ and Ross C. Lillie^2
1Illinois State Geological Survey, Prairie Research Institute, University of Illinois, Champaign,Illinois
²North Star Minerals, Traverse City, Michigan

Suggested citation:
Denny, F.B., W.J. Nelson, J.R. Breeden, and R.C. Lillie, 2020, Mines in the Illinois portion of the Illinois-Kentucky Fluorspar District: Illinois State Geological Survey, Circular 604, 73 p. and map.

Abstract

This report compiles into a cohesive document details of the individual mines within the Illinois portion of the Illinois-Kentucky Fluorspar District (IKFD). This document also contains brief sections concerning the mining methods, geology, historical production figures, and theories of the origin of the ore deposits. In 2012, the Kentucky Geological Survey produced a map of the IKFD that covers only the Kentucky portion. The mine location map that accompanies this document was designed to augment the Kentucky fluorspar mine map. During research activities for this project, we gained access to confidential unpublished files from several mining companies. Maps, exploration reports, drill logs, and production figures were scanned and are available upon request at the Prairie Research Institute. Although the last mines in Illinois ceased operations in 1995, there is potential for future mining activities in deeper, relatively unexplored strata. The authors hope this report and the scanned documents will be helpful for future exploration activities and to other interested parties.

Introduction

The Illinois-Kentucky Fluorspar District (IKFD) was, for most of the 20th century, the primary source of fluorspar for the United States. The strategic importance of fluorspar was heightened during World War II because of the use of fluorspar in steel manufacturing. Production of fluorspar ore in this region peaked shortly after World War II and was sustained until the 1970s, when competition from foreign suppliers began to erode the dominance of this mineral district. The early mines were originally operated by dozens of local entrepreneurs producing small tonnages of fluorspar, but in the 1930s, corporate ventures such as Ozark-Mahoning and the Aluminum Ore Company (a precursor of ALCOA) entered the picture. The larger companies erected modern processing mills that allowed a lower grade ore to be enriched into a commercial product. Historical photographs of mines and mining activities in this district provide a nice pictorial archive of these mines and are compiled in the book Fluorspar Mining: Photos from Illinois and Kentucky, 1905–1995.

“Fluorspar” is an industrial synonym for the mineral fluorite. The chemical formula for the mineral is calcium difluoride (CaF₂). The fluorspar ore found in the IKFD is usually not 100% CaF₂ and contains minor impurities, mainly calcite and quartz. The ore may also contain galena, barite, and sphalerite, which can be separated and sold. For much of the 19th century, mining concentrated on galena, and fluorite was considered a waste product. By the late 1800s, fluorspar was being utilized as a fluxing agent in the smelting of steel, which made fluorspar a valuable commodity. From 1914 to 1915, the ores of the IKFD accounted for more than 99% of fluorspar production in the United States. In about 1953 to 1954, the major use of fluorspar shifted from predominantly steel manufacturing to the manufacturing of hydrofluoric acid for the chemical and aluminum industries. The primary uses of fluorspar today include the production of hydrofluoric acid and various other chemicals, steel manufacturing, aluminum smelting, hydrofluorocarbon, and fluoropolymer production.

Production History

Statistics on fluorspar and metal mining in Illinois from 1925 through 1985 are available in the Illinois Department of Natural Resources Illinois Coal Reports. Published annually, the Illinois Coal Reports document the short tons of raw or crude ore mined in Illinois by company. The crude ore mined is milled or refined before being sold; therefore, the crude ore figures are larger than the finished or refined tonnage of fluorspar shipped. The refined or finished tonnage of fluorspar is reported in the U.S. Geological Survey (USGS) Minerals Yearbooks.

Available supply, demand, and economic conditions controlled the volume and sale price of fluorspar. The need for fluorspar increased during World Wars I and II and lessened during economic downturns, such as the Great Depression of the 1930s (Figure 1a). From 1925 to 1985, more than 125 individual companies produced fluorspar in Illinois, but the top 24 companies accounted for 97% of the total crude ore production in Illinois (Table 1). Changing ownership of mines and properties makes tracking fluorspar production by company difficult; thus, Table 1 provides only an estimate of raw fluorspar production. An asterisk in Table 1 indicates a discrepancy or error in the data related to that company. This could be due to typographical errors, erroneous data submitted by the mining company, or other human errors. Although the data have a few problems, the Illinois Coal Reports as a whole are an excellent source of raw production figures for the Illinois portion of the district.

Figure 1

Table 1  Production of “raw” crude ore in Illinois by company from 1925 to 1995.1
Company	Raw (short tons)	Years of production
Ozark-Mahoning (OZM) and related *	10,239,405	1938-1995
Minerva Oil Company, Inverness Mining Company, and Allied Chemical Company*	5,021,463	1944-1982
Aluminum Ore Company (ALCOA) and related	1,994,109	1936-1965
Rosiclare Lead and Fluorspar Company*	1,990,745	1925-1952
Crystal Fluorspar Company	411,799	1930-1951
Hillside Mines	310,231	1925-1954
Illinois Minerals*	190,704	1977-1979
Benzon	163,989	1925-1937
Goose Creek Mining Company	149,839	1952-1958
Victory Fluorspar Mining Company	138,281	1929-1945; 1952-1955
Hoeb Mining Company	87,610	1956-1963
G.B. Mining*	70,298	1948-1949
Patton and Sons	60,356	1956-1967
Fluorspar Products	60,078	1934-1947
A.H. Stacey	53,213	1946-1951
P.M.T. Mining	43,444	1949-1956
Hastie Mining*	41,650	1969; 1973-present
Mackey-Humm	40,088	1953-1956
Inland Steel	34,363	1945-1948
Knight, Knight, and Clark	23,650	1926-1938
Crown Fluorspar Company	23,021	1942
Yingling Oil Company*	21,557	1942-1948; 1951
Total top producers	21,169,893
Other producers	652,471
Estimated total raw short tons	21,822,364
1Data extracted from Illinois Coal Reports and other sources. An asterisk (*) denotes a probable discrepancy in the data (see text for details).

Subdistricts

C

• Cave-in-Rock Subdistrict

E

• Eichorn Area
• Empire Subdistrict

F

• Fluorspar Regional Maps
• Fluorspar Uncertain Maps

G

• Goose Creek Subdistrict

H

• Hamp Subdistrict

H cont.

• Harris Creek Subdistrict
• Hicks Dome
• Hobbs Creek Subdistrict

I

• Interstate Subdistrict

K

• Karbers Ridge Subdistrict

L

• Lusk Creek Subdistrict

R

• Rose Creek Subdistrict

R cont.

• Rose Creek Subdistrict2
• Rosiclare Subdistrict

S

• Southeastern Saline County
• Southern Pope County
• Stewart Subdistrict

T

• Tower Rock Area