152 
MINERALS YEARBOOK, 1967 
 
phate from Searles Lake brines in a plant at Trona, San Bernardino County.
The compound was converted to finished lithium carbonate before shipment.
Plant output was 1 percent above that in 1966. 
 
 Magnesium Compounds.—Production, sales, and producer consumption of
magnesium compounds were lower than in 1966. The decline was particularly
significant in refractories use, reflecting a depressed steel indutry. FMC
Corp. extracted magnesia from salt-works bitterns at plants in Alameda and
San Diego Counties. The San Diego plant also produced magnesium chloride.
Kaiser Aluminum & Chemical Corp. and Merck & Co., Inc., recovered
magnesia from sea water at plants in Monterey and San Mateo Counties, respectively.
Kaiser consumed most of its output in the manufacture of refractories, most
of which were used in the integrated steel plant of Kaiser Steel Corp., San
Bernardino County. Merck also produced magnesium carbonate and magnesium
trisilicate in its San Mateo County plant where an extensive modernization
program was completed in 1967. 
 
 Mica.—Western Industrial Minerals mined mica (sericite schist) near
Ogilby, Imperial County, and dry-ground the material for sale to a paint
manufacturer. The Bouquet Canyon property near Saugus, Los Angeles County,
was idle throughout the year, and exploration work only was reported from
the Hyalumsil claims near Quincy, Plumas County. 
 Kelly-Moore Paint Co., Inc., mined and stockpiled mica schist near LeGrande,
Mariposa County, but none of the rock was processed or shipped. 
 
 Pcrlite.—The Fish Springs quarry, Inyo County, operated by American
Perlite Co., was the State's only active perlite property. A small tonnage
of stockpiled crude perlite at the Alvo mine, Napa County, of Perlite Materials
Co. was expanded and used by the producer for lightweght aggregate. American
Perlite shipped to its affiliate and other expanding plants in Los Angeles
County. 
 A total of 11 expanding plants were operated in five counties, seven in
Los Angeles County and one each in Napa, Contra Costa, San Diego, and Sonoma
Counties. Plants in the last three named counties purchased all their crude
require- 
ments from sources outside the State. Five of the seven Los Angeles plants
also obtained some crude perlite from out-of-State. 
 Crude sales declined 26 percent and sales of expanded perlite dropped more
than 32 percent, compared with 1966. About 
37 percent of the expanded output was used for filter aids, 30 percent for
plaster aggregate, 9 percent as filler, 8 percent for soil conditioner, 7
percent as concrete aggregate, and 9 percent for all other uses including
loosefill insulation. 
 
 Potassium Salts.—American Potash & Chemical Corp., division of
Kerr-McGee Corp., the State's only producer of potassium compounds, extracted
potassium chloride from Searles Lake brines at Trona, San Bernardino County,
and converted part of the output to potassium sulfate. Overall production
was above that of 1966. Although more sulfate was produced, sales were lower.

 
 Pumice.—Combined output of pumice, pumicite, and volcanic cinder rose
nearly 50 percent above 1966 figures but sales of prepared material were
9 percent lower. The overall increase in production was attributed to large
tonnage of volcanic cinder used in road construction and maintenance by Federal,
State, and County agencies. Crude sales represented 86 percent of the total
output with only 14 percent of all materials having been crushed, screened,
ground, or otherwise processed before shipment. 
 
 Salt.—.Sait production continued its rising trend and established
a record high in 1967. Seven companies and one metropolitan water district
reported crude salt production by solar evaporation. Most of the output was
recovered from sea water at evaporating ponds in three San Francisco Bay
Area counties—Alameda, San Mateo, and Napa. Additional production came
from seawater ponds in Monterey, Orange, and San Diego Counties, and from
inland dry lakes in Kern and San Bernardino Counties. Leslie Salt Co., the
State's largest producer, made all grades of salt in its Alameda County plant
at Newark. Morton Salt Co. refined purchased crude salt in an adjacent plant.
All other companies produced the crude product only. Leslie also produced
some rock salt at Bristol Lake, San Bernardino County. Nearly half the total
output went to