K. K. Kaysenov, A. A. Kurmankozhaeva GB 6
PROBLEMS OF INDUSTRIAL USING OF THE MAN-CAUSED ORE DEPOSITS ON THE MINES OF KAZAKHSTAN
Problems of the industrial using of the
man-caused wastes as well as problems of decreasing
exploitation losses of the ores are posed more sharply under conditions of
exploiting the largest ore basins of Kazakhstan: Zhezkazgan copper,
Mirgalimsay, Zhayrem and Zyryanovsk polymetallic, Sokolovo-Sarbay iron-ore and
South-Kempirsay chromites deposits (exploited both in open air and underground
ways). Industrial exploitation of the wastes and decrease of the ores
losses are presented as a constituent part of the whole problem of the
protection and rational complex usage of the mineral wealth.
Theoretical aspects of the mentioned
processes in principle concern the following problems: 1) the geological
knowledge of deposit; 2) ecological economic efficiency of the technology for
preparing and exploiting the ore bodies, and 3)
the ore extraction from man-caused objects of mineral raw material of various
complexity. As to the first problem its solution is oriented toward creating
the starting basis for exploitation in the form
of a model describing tendencies, rules and
other peculiarities intrinsic to the geometry
and deposition of the ore bodies and space statistical distribution of the main
components and ore types. The second problem consists in up-dating and
developing new effective technologies for preparing and exploiting ore bodies taking into account both current and
special technique. The problems of the ores extraction from the man-caused
objects of the mineral raw material are especially important. Their solution is
oriented to create ecologically and economically efficient technology to
extract the ore from the technogeneous dumps and waste formations still bearing
the mineral raw material and also to prepare respective reserves left as losses
in the bowels due to various man caused reasons.
The complex industrial using of the
technogeneous deposits and developing effective exploration and technological
methods for that purpose are of fundamental importance for mineral resources saving, environmental and
mineral resources protection. A wasteless technology itself represents a set of
technological means for the complete and complex usage of natural resources,
and for minimising both waste volume and harmful substances effect to the
environment.
Wastes produced by the mining activities
are of very high value for the industry: man-caused technogeneous formations,
dumps of dirt, substandard ores, low grade and
impoverished ores, wastes of the ore dressing and metallurgy plants, wastes of
the heating power stations (ashes,
slag) etc. It is necessary to note an initial step of the development processes
for using of these wastes left by the mining
industry: different kinds of building materials, ceramics and asbestos-cement goods and many other products can be made. They are
used as stowing material in subterranean works,
in the railway and road-transport building and also for reclaiming soils, as
agrochemical raw material in the agriculture etc.
In the CIS countries during the
exploitation of minerals and their following processing from ore-dressing – up
to the concentrate following material is annually deposited: altogether more
than two milliards of the cubic meters of different rocks and wastes of ore
dressing, more than 100 millions tons of the metallurgy slag, 90 millions tons
of the coal ashes and around 140 millions of
tons of the caught dust and furnace carry etc. Specific output of the rock mass represented as overburden rocks in the open pits of Kazakhstan represents in average
80 - 90% of the extracted volume of the all rock mass. In the Republic more
than 600 millions tons of the rock mass (consisting of minerals and overburden
layers) are extracted annually from the earth. About 95 - 98% of the extracted
rock mass is stored as dumps and only 2 - 5% is used to get the useful final
product. Wastes partially used for the production of the building materials,
mineral chemical fertilisers, filling of the rock excavations etc. are
significantly less than the annual output of these dumps. Only on the plants of
the non-ferrous metallurgy of Kazakhstan about 6 milliards of tons of the
wastes (75% of mining rocks of the accompanying extraction and overburden, 23%
- wastes of the ore dressing, 2% - wastes of the metallurgy production) are accumulated
and they occupy surface areas more for than 14 thousands of hectares.
The harm from the atmosphere, hydrosphere
and lithosphere pollution by the man-caused mineral objects is significant and
often exceeds the harm caused by the emissions and waste disposal of the
metallurgy factories, ore-dressing factories, mines and mining pits. In this
aspect it is necessary to specify man-caused formations of the Donskoy,
Belogorsky, Karagaylinsky ore mining and processing enterprises, Zhezkazgan,
“Kazvolfram” and wastes of various metallurgy production enterprises volumes of
which are accumulated in enormous quantities.
The problem of developing the man-caused
formations of mineral resources consists of a
broad spectrum of research. It contains a system of technological
solutions and ways of the forming of the working-off of the man-caused
deposits, ecological and social economical methods of their assessing and
binding with nature protection measures, modelling methods for quality and mechanical indicators of
the man-caused formations, technical economic estimation of their working off
and industrial usage of the technology
minimising their output. Wasteless technology and production are the most
perspective modern way how to extract and process mineral raw materials
permitting to solve the problem of a more complex use of the mineral resources.
It is also the main factor of both the environment protection and rational use
of natural resources. In small wastes production resulting from practical activities
the harmful effect on the environment is not higher than the level permitted by
the sanitary norms, but on the other hand for technical, economic,
organisational and other reasons a considerable part of the raw materials and
materials is transported to the dumps for the burial or for the long-term
storage.
One of the indispensable conditions for
developing the wasteless production consists in combining technologies allowing
the maximum utilisation of all elements of the incoming raw material and their
consumption within the enterprises by using one kind of material for producing
another kind etc. up to the complete waste liquidation.
Main ways of the solution of the problems
of the industrial exploitation of the man-caused technogeneous resources are as
follows: rational ways of the receiving following useful production, keeping
off-balance ores and potentially useful accompanying extracted rock masses;
forming of the man-caused deposits with the optimal parameters; release of the
earth resources; decrease of the environment contamination with the solid
wastes, and taking off the soil, capital investments for developing new
deposits at the expense of using the man-caused raw material; partial release of
the powers of the processing enterprises; substantiation of the consequences
for storing different kinds of ores.
All the above stated
facts allow to make conclusion that it is necessary to seek methods of how to
evaluate the quality and geometrisation of the man-caused deposits, their geological
and geometrical assessing, reclaiming man-caused objects, establishing
technological schemes for utilising accumulated wastes (technological mapping),
extraction, selective extraction and processing of different technological
kinds of ores for their protection against secondary changes as a result of
physico-chemical processes by temporary reclaiming their surfaces, for
substantiation of the condition of the off-balance ores and useful layers in
the overburden that should be stored as man-caused deposits, substantiation of
their average quality on the basis of using analytical calculations of
statistical indicators and mathematical prediction methods.
One of the important directions
decreasing the losses of the ores is the problem of how to decrease outputs of
the man-caused formations of the rock mass during the mining process. It is
necessary to specify two approaches to solve this problem of resources saving.
The first approach consists in developing new effective or up-dating already
existing methods of the metals extraction from the man-caused deposits, in an
intensification of their usage; in increasing the efficiency of the ways of the
solution of the technological objectives of the forming and working off of the man-caused deposits, social-economical methods
of the estimation of the mastering of the man-caused resources, ways of their
utilisation. The second approach is oriented to find how to diminish the mixing
of different kinds of the rock mass; this approach includes losses of the industrial
ores directly in the process of the extraction works; optimisation of the
conditions for forming volumes of the man-caused formations depending on the
losses, quality and indicators of the efficiency of the ore exploitation;
substantiation of the optimal proportions between these parameters - indicators
and progressive variants of the technology of the management of the selective
extraction with taking into account the specificity of the drilling and
blasting operations and direction of
the development of the rock works that provide minimal losses of the ores
during the exploitation process as well as geological technological methods of
the metals extraction from balance and off-balance ores.
One of the perspective directions for
utilising wastes of the rock metallurgy production is the method of the closely
grouped lixiviation which as progressive method
founds application in the CIS countries and recently has become competitive
traditional processing of the solid, precious and radioactive elements (copper, manganese, gold, silver, uranium).
Efficiency of this method is given by results of the enlargement of the raw
material base of the metallurgy enterprises; reduction of the volumes of the
transported raw material; diminishing of the processing costs; diminishing of
volumes and areas occupied by the wastes of the production and decreasing costs
for restoring these areas.
Ore masses located in the dumps are
subjects to significant change in the process of the natural factors impact.
That is why in many cases it is necessary to perform geological survey works in order to account and estimate mineral raw
materials in these dumps. The recommended method of the operational metering of
the lost substandard ore masses, extracted and stored apart during the
exploitation process is based on the identification of their initial indicators
by an instrumental survey and samples testing of these stores. Practice of
separately storing the lost substandard ore masses representing mix of the lost
ore and adding to it layer or ill-conditioned (base) ore in local mines shows
the possibility how to organise the lixiviation and storage of them during the
exploitation. Costs for the process of storing irrevocably lost ore masses are
compensated at the expense of the extracted value in case of their usage in the
future at the expense of new mining and ore processing technologies.
Industrial wastes as an enormous source
of the mineral raw material represent a potential ecological threat. According
to research data annually in average up to 100 kg of the dust is blown from one
unit of the dump surface (sq. m) into the atmosphere and around 2,5 tons from
one hectare of the surface of dry tailing dumps.
Necessity of the radical scientifically
based developments and solutions of the problem of usage of how to use wastes
of rock-metallurgy productions is especially important for Kazakhstan where
broadly developed mining and processing fields require rational extraction and
complex usage of mineral resources.
Approximately up to 70% of the industrial
wastes contain useful components, silicates etc. Such wastes of the rock working when used would have been
absolutely inefficient very rarely. In the Republic the stocks of the wastes of
the rock mining productions and rock mining plants and factories are enormous.
We have evaluated the efficiency of the
industrial exploitation of technogeneous man-caused mineral wastes left by the
previous mining activities by using dynamics of the changes in the net mining
cost in dependence on the lost ores and wastes.
Optimisation model
of the interrelationship of the net cost of exploiting 1 ton, net cost of the
discharge of the overburden and output of the excavator is received as follows:
(1)
where: KBC -
coefficient of the increase of the net cost of overburden (tg/t), KП, Kr
– coefficients of the losses and mixing the ore (proper unit); Qсм
- shift output of the excavator (thousands of tons). Empirical
parameters a, b, n, c on the absolute value differ for various deposits and
depend on actual value of the net cost of the mining, overburden, losses and
impoverishing of the ores, output of the excavator and dynamics of their
changing in the appropriate segments of the deposit.
As it is seen from the obtained
estimations, the consequences of the effect of quantitative and qualitative
losses reflect the value of the prime cost of the exploitation and man-caused
mineral wastes. Therefore the change of technical economic indicators of the
enterprise shown in its activity is worthy to be represented as the economic
consequences:
(2)
Estimation of the generalised prime cost of the ore mass extraction under conditions of the
Donskoy quarries based on the statistical analysis of actual mining indicators
is as follows:
(3)
The net costs of the man-caused dilution
poor (Tрб) and substandard lost (T нт ) ore masses
are equal:
(4)
where:
Cдоб and Tрб are net costs of
the mining and overburden respectively (tg/ ton), Cтр , Cскл, Cхр – respective net
costs of the transportation, storage and keeping of man caused waste (tg/ton).
From this we obtain:
(5)
The
model of economic consequences of expressed varieties of ore masses under
conditions of the mining pits of Donskoy taking into account the
above-mentioned formulas is expressed by the following equation:
(6)
where:
a, b, c, d – statistical parameters of the dependence (a=139,23; b=1,58;
c=0,01; d=2,09).
After
a further reorganisation the multiparameter model for expressing the
consequences caused by technogeneous sorts of ore masses outputs in the course
of exploitation of the chromites ores looks as follows:
(7)
Its simplified form is as
follows:
(8)
Where: Iпор
output of the overburden dirt (appr. unit);
- value of the output
of man-caused impoverished –ore mass base (
)
that is part of the mining (appr. unit);
- value of the output of
ill-conditioned lost ore mass (
) that is part of the overburden (appr.
unit);
Tт - sum quantity of the kinds of
the man caused mineral wastes (Tт= Tрб+ Tнт) in the mining of
the chromites ores (thousands of tons).
As can be seen from the obtained
multiparameter model (8), the efficiency of exploiting deposits of valuable
ores is directly influenced by outputs of the mineral technogeneous wastes and
ores lost during the mining process. Ecological consequences caused by
technogeneous kinds of wastes change proportionally to their values, and they
also increase with the increasing growth of their net costs in the course of
the exploitation process.