Page 360 - Solid Waste Analysis and Minimization a Systems Approach

338 MINING APPLICATIONS

23.3 Economics

Generally speaking, the mining sector generates relatively high revenue per employee
versus other sectors. This increased revenue and cash flow allow this sector to select
waste minimization opportunities with high initial investments.

23.4 Constraints and Considerations

There are several constraints to recycling in the mining sector, such as

■ Limits to market access
■ Limits on the importation of recyclable materials
■ Added transportation and administrative costs
■ Added government regulations

Extraction is the first phase of hard rock mining which consists of the initial removal
of ore from the earth. Beneficiation follows and is the initial attempt at liberating and
concentrating the valuable mineral from the extracted ore. After the beneficiation step,
the remaining material is often physically and chemically similar to the material (ore
or mineral) that entered the operation, except that particle size has been reduced.
Beneficiation operations include crushing; grinding; washing; dissolution; crystalliza-
tion; filtration; sorting; sizing; drying; sintering; pelletizing; briquetting; calcining;
roasting in preparation for leaching; gravity concentration; magnetic separation; elec-
trostatic separation; flotation; ion exchange; solvent extraction; electrowinning;
precipitation; amalgamation; and heap, dump, vat, tank, and in situ leaching. The
extraction and beneficiation of minerals generates large quantities of waste.
Mineral processing typically generates waste streams that generally bear little or no
resemblance to the materials that entered the operation. These operations most often
destroy the physical structure of the mineral, producing product and waste streams that
are not earthen in character. Mineral-processing operations generally follow beneficia-
tion and include techniques that often change the chemical composition of the ore or
mineral, such as smelting, electrolytic refining, and acid attack or digestion. Regulation
affecting mineral processing wastes was developed through a long process covering the
period from 1980 to 1991. It involved numerous proposed and final rule makings and
federal litigation.

23.5 Implementation and Approach

To implement waste minimization strategies several options are available. The federal,
state, and local governments offer numerous support programs. In addition, the orga-
nization’s current waste hauler may have options to reduce solid waste or divert it from