RU2229938C1 - Method of upgrading of sulfide ores - Google Patents

Abstract

FIELD: mining industry; upgrading of polymetallic sulfide ores. SUBSTANCE: the invention presents a method of upgrading of sulfide ores and may be used in mining industry for upgrading of polymetallic sulfide ores and in particular copper-nickel ores. The technical result is a decrease of labor inputs and power consumption costs at upgrading, decrease of hazardous impurities discharge in the atmosphere and improvement of an environment in the area of the ore processing. The method provides that the initial ore is comminuted up to the sizes of no more than 0.25 mm. Then the comminuted ore is subjected to the flotation separation for nonmetallic minerals and middlings. The middlings dehydrated up to residual humidity of no more than 2 % is directed for the further processing, that is conducted by its feeding in a stream of an indifferent gas in a plasma-chemical reactor, where a finely dispersive phase of the middlings in the stream of the indifferent gas is subjected to high-speed, high-temperature heating. After the heated mixture exit from the plasma-chemical reactor, it is exposed to sharp cryogenic refrigeration with consequent separation of elemental sulfur and a powdered bulk concentrate. EFFECT: the invention allows to decrease labor inputs, power consumption and discharge of hazardous impurities in the atmosphere in the process of polymetallic sulfide ores upgrading. 4 cl, 1 tbl, 1 ex

Description

The invention relates to the field of mineral processing, in particular sulfide polymetallic ores, and can be used in the processing of copper-nickel sulfide ores.

A known method of enrichment of copper-Nickel ores, in which all the final products, including industrial sulfur, are obtained by flotation enrichment with an intermediate process of electromagnetic separation (see, for example, S.I. Polkin and others. Enrichment of non-ferrous metals. - M .: Nedra, 1983, p. 246-248).

The disadvantages of this method are the large number of flotation stages necessary to extract all useful products, as well as a long and laborious enrichment process.

A known method of beneficiation of sulfide copper-nickel ores, including ore preparation, wet grinding of the material and its hydraulic classification, the separation of non-ferrous metal sulfides and native platinum metals from pulp of the classified material by flotation and gravity methods into independent products (see, for example, RF patent No. 2144429 , CL B 03 B 9/00, publ. 20.01.2000).

The main disadvantages of this method are the presence of long cycles of flotation operations, low efficiency of the extraction of useful components, as well as the need for further pyrometallurgical processing of the obtained concentrates with the release of a large amount of sulfur dioxide into the atmosphere. At the same time, some of the valuable metals are not extracted and accumulate in tailings.

The technical problem to which the present invention is directed is to improve the technology of sulphide ore dressing to exclude the emission of sulfur dioxide into the atmosphere and increase the efficiency of the process of sulphide polymetallic ore dressing.

The technical result that can be obtained by using the present invention is to reduce the cost of labor and energy costs during enrichment, as well as significantly reduce harmful emissions into the atmosphere and improve the environmental situation in the ore processing area.

The problem is solved due to the fact that in the method of beneficiation of sulfide ores, including grinding the initial ore, its flotation separation into non-metallic minerals and an intermediate product and further processing of the intermediate product to obtain a collective concentrate, grinding the initial ore is carried out to a particle size of not more than 0.25 mm , after flotation separation, the intermediate product is dehydrated to a residual moisture content of not more than 2%, and the intermediate product is further processed by feeding it to de fine phases in the stream of neutral gas plasma followed by a high-speed high-temperature phase by heating finely divided intermediate product stream of neutral gas cryogenically cooled to obtain elemental sulfur and particulate bulk concentrate.

Preferably, the cryogenic cooling of the finely divided phase of the intermediate in the neutral gas stream is carried out with liquid neutral gas.

It is advisable to conduct plasma high-speed high-temperature heating in a neutral gas stream of the finely dispersed phase of the intermediate product at a plasma temperature of neutral gas up to 10,000 degrees Celsius.

In addition, it is preferable to use nitrogen as a neutral gas.

The indicated set includes features, each of which is necessary, and all together are sufficient to achieve the set technical result in all cases of using the invention, to which the requested amount of legal protection applies.

The method is as follows.

The source ore is crushed. Depending on the type of ore, the degree of crushing may be different. For example, during the enrichment of disseminated ores of the Norilsk-1 deposit, sulfide minerals form dense aggregates that are separated from gangue minerals by grinding to 40% class - 0.074 mm. To separate finely disseminated sulfide minerals, the ore must be ground to 63% of the class - 0.074 mm. In any case, the initial ore is crushed to a particle size of not more than 0.25 mm, after which flotation separation of the intermediate product from non-metallic minerals is carried out.

Dehydrated to a residual moisture content of not more than 2%, the intermediate product is sent for further processing, which is carried out in a plasma-chemical reactor (plasmatron). At the entrance to the plasma chemical reactor, the crushed and dehydrated intermediate product is fed into a stream of neutral gas, for example nitrogen. The formation of a dusty gas mixture of a finely dispersed phase of the intermediate product and a neutral gas. The specified dust-gas mixture enters the plasma-chemical reactor, where it successively passes through the electrode belts, between which an arc discharge is created with a temperature inside the plasma of up to 10,000 degrees Celsius.

In this case, the required temperature of the finely dispersed phase of the intermediate product can be achieved both by controlling the speed of passage of the dust-gas mixture between the electrodes, and by controlling the amount of intermediate product supplied per unit time.

When a certain temperature is reached, due to the composition of the initial ore, the mixture goes into a gaseous state, the polysulfides decompose with the release of constituent elements and, in the first place, elemental sulfur.

The decomposition products of polysulfides after a plasma-chemical reactor are immediately fed to a cryogenic cooling chamber with liquid neutral gas. Sudden cooling prevents the occurrence of chemical reactions in the mixture and promotes the conversion of gaseous elements into powder elements.

Sulfur is first removed from the resulting mixture of powdered metals and powdered sulfur. A significant difference in the physical characteristics of sulfur and metals allows the separation of sulfur by flotation, sedimentation in a liquid or gas stream, the use of hydraulic or gas cyclones, in an electrostatic field, by centrifugation, or a combination of the above methods.

The resulting powdered metals are a collective concentrate, the further separation of which can be done by any known method.

At the same time, sulfur is completely removed from the further technological cycle and sulfur dioxide emissions are excluded during pyrometallurgy, and in addition, due to complex processing, metal losses are eliminated.

Example.

Pilot plant for processing 50 t / h of sulfide raw materials of the pyrrhotite type, having the composition, wt.%:

Nickel 2.4-2.9

Copper 3-4.5

Cobalt 0.11-0.13

Sulfur 25-27

Iron 38-42

Non-metallic minerals 26-28

After flotation separation of non-metallic minerals, a mixture of polysulfides, crushed to a size of 0.1-0.2 mm, in a stream of nitrogen enters the column-type plasma chemical reactor, where it successively passes through three electrode belts, between which an arc discharge is created with an average temperature inside the plasma of about 6000 degrees Celcius.

The decomposition products of polysulfides after a plasma chemical reactor are immediately fed into a cryogenic cooling chamber with liquid nitrogen. The cooled product, which is a mixture of elemental sulfur powders and metals, is fed into the sulfur separation column by an ejected stream of nitrogen. The mixture of metal powders of nickel, copper, iron, cobalt and platinum metals purified from sulfur is supplied to the column type apparatus for sequential separation by the carbonyl method.

The material composition of the mixture after separation of sulfur is presented in the following table.

If necessary, the operation of the installation can be provided by a power unit based on a gas turbine plant operating on natural gas.

Claims (4)

1. A method of beneficiation of sulfide ores, including grinding the initial ore, its flotation separation into non-metallic minerals and an intermediate product and further processing of the intermediate product to obtain a collective concentrate, characterized in that the grinding of the initial ore is carried out to a particle size of not more than 0.25 mm after flotation the separation produces dehydration of the intermediate product to a residual moisture content of not more than 2%, and further processing of the intermediate product is carried out by feeding it in the form of a finely divided phase in a stream of neutral gas followed by plasma high-speed, high-temperature heating of the finely dispersed phase of the intermediate product in a stream of neutral gas and cryogenic cooling to obtain elemental sulfur and bulk powder concentrate. 2. The method according to claim 1, characterized in that the cryogenic cooling of the finely dispersed phase of the intermediate product in a neutral gas stream is carried out with liquid neutral gas. 3. The method according to claim 1, characterized in that the processing of the intermediate product by plasma high-speed, high-temperature heating of the finely dispersed phase of the intermediate product in a neutral gas stream is carried out at a plasma temperature of neutral gas up to 10000 ° C. 4. The method according to any one of the preceding paragraphs, characterized in that nitrogen is used as a neutral gas.