See:acid-etch tube
Metallurgically acid material (usually some form of silica) used as a
flux. Bennett
Earth materials that contain sulfide minerals or other materials that, if
exposed to air, water, or weathering processes, form acids that may create
acid drainage.
a. A descriptive term applied to those igneous rocks that contain more
than 60% silica. Acidic is one of four subdivisions of a widely used
system for classifying igneous rocks based on their silica content:
acidic, intermediate, basic, and ultrabasic. AGI
b. Applied loosely to any igneous rock composed predominantly of
light-colored minerals having a relatively low specific gravity.
CF:felsic
The process of forcing acid into a limestone, dolomite, or sandstone in
order to increase permeability and porosity by dissolving and removing a
part of the rock constituents. It is also used to remove mud injected
during drilling. The general objective of acidization is to increase
productivity. Syn:acidizing
To treat a limestone or dolomitic formation with dilute hydrochloric acid
to enlarge its void spaces. Wheeler, R.R.
See:acidization
Metallurgical process for dissolution of metals by means of acid solution.
Examples include extraction of copper from oxide- or sulfide-bearing ore
and dissolution of uranium from sandstone ores. Acid leaching can occur on
heap-leach pads or in situ.
a. Acidic drainage from bituminous coal mines containing a high
concentration of acidic sulfates, esp. ferrous sulfate.
See also:acid water
b. Drainage with a pH of 2.0 to 4.5 from mines and mine wastes. It results
from the oxidation of sulfides exposed during mining, which produces
sulfuric acid and sulfate salts. The acid dissolves minerals in the rocks,
further degrading the quality of the drainage water. AGI
a. Mine water that contains free sulfuric acid, mainly due to the
weathering of iron pyrites. A pit water, which corrodes iron pipes and
pumps, usually contains a high proportion of solids per gallon,
principally the sulfates of iron, chiefly ferrous and alumina.
See also:acid water
b. Where sulfide minerals break down under chemical influence of oxygen
and water, the mine drainage becomes acidic and can corrode ironwork. If
it reaches a river system, biological damage may also result.
Pryor, 3
Calcium carbonate, CaCO3 , magnesium carbonate, MgCO3 , and
china clay, which neutralize free acids, thereby preventing explosives
from decomposing in storage. They also have a cooling effect and tend to
reduce the sensitivity of the explosive. Cooper
Low-phosphorus pig iron treated in an acid (silica or sand)-lined furnace.
Mersereau, 2
See:siliceous ore
A steelmaking process--Bessemer, open-hearth, or electric--in which the
furnace is lined with a siliceous refractory, and for which pig iron low
in phosphorus is required, as this element is not removed.
See also:acid steel; basic process. CTD
In the coke products industry, a person who recovers sulfuric acid used in
processing coke-gas byproducts by cooking sludge with steam in acid
regenerator pots. Syn:acid regenerator
A general term for those types of refractory material that contain a high
proportion of silica; e.g., silica refractories (greater than 92% SiO (sub
2) ) and siliceous refractories (78% to 92% SiO2 ). The name
derives from the fact that silica behaves chemically as an acid and at
high temperatures reacts with bases such as lime or alkalies. Dodd
Refractory product made of clay-silica mixture or pure silica.
Rosenthal
Drainage that occurs as a result of natural oxidation of sulfide minerals
contained in rock that is exposed to air and water. It is not confined to
mining activities, but can occur wherever sulfide-bearing rock is exposed
to air and water. Abbrev. ARD.
Slag that contains substantial amounts of active silica.