718 
MINERALS YEARBOOK, 1967 
 
 Installation of electrostatic precipitators capable of removing 99 percent
plus of the solids from the kiln emission was begun late in 1967. By this
approximately $1 mulion addition to the cement plant, the State has set an
example for air-pollution control in the Rapid City area. Although the micron-size
particles collected have little or no commercial value, the investment should
pay off in improved public relations. 
 
 Clays.—Bentonite and common clays were produced in Butte County and
shale in Pennington County. Bentonite was mined by American Colloid Co. and
International Minerals & Chemical Corp. (1MG). The only processing plant
in the State, operated by American Colloid Co. at Belle Fourche, processed
bentonite mined in Butte County, S. Dak., and Crook County, Wyo.; the processed
bentonite was marketed under the trade name Volclay. The bentonite mined
by 1MG was processed at its new plant at Colony, Wyo. 
 Black Hills Clay Products Co. at Belle Fourche, the only brick manufacturer
in South Dakota, mined common clays from 
two locations for manufacturing building brick. Shale mined near Rapid City
was used as an ingredient for manufacturing cement at the State-owned cement
plant and for making lightweight aggregate by Light Aggregates, Inc. 
 
 Feldspar.—.Feldspar production increased in Custer and Pennington
Counties, even though the number of operating mines decreased by one in each
county. The two plants processing feldspar were the 1MG grinding plant at
Custer, the principal processor of potash-type feldspar, and the Northwest
Beryllium flotation mill at Keystone, which produced soda-type feldspar.

 
 Gypsum.—South Dakota Cement Commission, the only producer and consumer
of gypsum in the State, produced 12,221 tons from its open-pit mine in Pennington
County. Of this output, 11,907 tons were used for manufacturing cement; the
remainder was stockpiled. 
 
 Lime.—The continued increase in lime production was attributed to
a vertical kiln installed late in 1966 at the Pete Lien & Sons lime plant
at Rapid City. According 
 
Table 6.—Sand and gravel production in 1967, by counties 
 
(Thousand short tons and thousand dollars) 
County 
Quantity 
Value 
County 
Quantity 
Value 
Aurora                      
58 
$69 
Jerauld                      
21 
$21 
Beadle                      
149 
145 
Jones                       
189 
189 
Bon Homme                  
Brookings                    
252 
740 
232 
753 
Kingsbury                   
Lake                        
120 
98 
127 
88 
Brown                      
453 
576 
Lawrence                    
587 
603 
Brule_                      
271 
274 
Lincoln                      
79 
81 
Buffalo                      
Butte                       
14 
173 
14 
173 
Lyman                      
McCook                     
61 
159 
62 
160 
Campbell                    
Charles Mix - 
207 
112 
222 
111 
McPherson                   
Marshall                     
95 
90 
98 
103 
Clark                       
320 
320 
Meade                      
287 
287 
Clay                        
89 
64 
Mellette                     
437 
437 
Codington                   
Corson                      
Custer                      
Davison                     
707 
186 
259 
398 
808 
153 
239 
424 
Minnehaha                   
Moody                      
Pennington                   
Perkins                      
547 
578 
600 
31 
478 
593 
572 
39 
Day                        
Deuel                       
475 
103 
495 
105 
Potter                       
Roberts                     
305 
239 
305 
279 
Dewey                      
10 
10 
Sanborn                     
201 
203 
Douglas                     
262 
278 
Shannon                     
2 
2 
Edmunds                    
Fall River                   
Faulk                       
Grant                       
91 
120 
152 
218 
92 
120 
152 
218 
Spink                       
Stanley                      
Sully                        
Todd                       
147 
73 
122 
34 
149 
73 
122 
34 
Gregory                     
Haakon                     
102 
41 
104 
41 
Tripp                       
Turner                      
80 
105 
79 
123 
Hamlin                      
253 
276 
Union                       
333 
341 
Hand                       
258 
231 
Walworth                    
94 
115 
Hanson                      
Harding                     
Hughes                      
Hutchinson                   
118 
164 
78 
180 
118 
164 
74 
176 
Washabaugh                 
Yankton                     
Ziebach ~     
31 
182 
133 
—-— 
31 
189 
133 
  
Hyde                       
68 
68 
Total           ~      
13,463 
13,737 
Jackson                     
322 
322