282 MINERALS YEARBOOK, 1985 
 
 The tonnage of clays used for refractories decreased slightly and constituted
6% of total clay produced. An increase in the use of high-alumina clay-based
refractories, in particular, calcined kaolin grogs, in monoliths offset the
decline in production of the more conventional refractory bricks and shapes.'
The major refractory consuming industries—cement, foundry, glass,
ferrous
and nonferrous metals—continued to undergo major changes in technology
and production levels for their products. Metal imports further exacerbated
the industry's problems. 
 Filler.—All kinds of clay have been used to some extent as fillers
in one or more areas of use. Bentonite, fuller's earth, and kaolin are the
principal filler clays. Kaolin, either air-floated, water-washed, low-temperature
calcined, and/or delaminated, is used in the manufacture of paper, rubber,
paint, and plastics. Fuller's earth is used primarily in pesticides and fertilizers.
Clays are in pesticides and fertilizers as either thickeners, carriers,'
diluents, or prilling agents. Bentonites were used mainly in animal feeds.

 Of the total clay produced, 11% was used in filler applications; of this,
kaolin accounted for 89%; fuller's earth, 7%; bentonite, 3%; and ball clay,
common clay and shale, and fire clay, the remaining 1%. Kaolin consumed as
fillers decreased slightly to 4.2 million tons. An approximate 8% decline
in paper coater-grade kaolin, which constitutes 54% of the total filler and
extender category, was largely responsible. Increases occurred in most of
the other filler categories for kaolin, except for paint and'plastics, which
decreased 13% and 8%, respectively. The paper filling and pesticides end
uses increased 19% and 59%, respectively, while the other increases were
more modest, generally under 6%. The total quantity of fuller's earth used
in pesticides and related products, such as fungicides, increased nearly
19% over that of 1984. 
 Absorbent Uses.—Absorbent uses for clays accounted for over 1.6
million
tons, or about 4% of total clay consumption. Demand for absorbents increased
8%. Fuller's earth was the principal clay used for absorbent purposes, and
this application accounted for 84% of its entire output. Demand for clays
in pet waste absorbents, 
representing nearly 49% of absorbent use, decreased 15%. Use in floor absorbents,
chiefly to absorb hazardous oily substances, accounted for another 39% of
the absorbent demand, which rose 14% above that of 1984. An upturn in the
industrial sector, large consumers of floor absorbents, and the economy in
general were responsible for the increased consumption. 
 Drilling Mud.—Demand for clays in rotary-drilling muds decreased
12%
to about 1.3 million tons and accounted for nearly 3% of total clay production.
This decrease reestablished the downward trend, except for the increase noted
in 1984, begun in 1982 when a combination of excess oil production and economic
uncertainties resulted in lower oil and gas well-drilling activities, which
depressed bentonite demand. Oil and gas well-drilling activity softened further
at yearend because of additional overproduction. Swelling-type bentonite
remained the principal clay used in drilling-mud mixes, although fuller's
earth, used mostly in saltwater drilling techniques, and nonswelling sodium-activated
bentonites, were also used to a limited extent. Bentonite and fuller's earth
accounted for nearly 100% of the total amount of clay used in this category.
Small amounts of ball clay and kaolin were used in specialized formulations.

 Floor and Wall Tile.—Common clay and shale, ball clay, kaolin,
and
fire clay, in order of volume, were used in manufacturing floor, wall, and
quarry tile. This enduse category accounted for about 1% of the total clay
production. Downsizing of homes, in part due to the need for remaining competitive
in the marketplace, has largely ended with declining interest rates. 
 Pelletizing Iron Ore.—Bentomte continued to be used as a binder
in
forming indurated iron ore pellets. Demand decreased nearly 28% to about
291,000 tons. Inroads of inexpensive Mediterranean area bentonite, largely
sodium-activated, into the traditional U.S. clay marketing area of the Great
Lakes, coupled with lower demand due to changing technology, metal imports,
and shrinking production levels, have all combined to lessen the demand for
domestic bentonites in this category.