RU2244028C1 - Method of depleting slags from smelting of oxidized nickel ores - Google Patents

Abstract

FIELD: nonferrous metallurgy.

SUBSTANCE: claimed method comprises combining slags using extraction principle with number of extractions n approaching infinity. Depleting agent efficient in presence of reducing agent is selected from materials enriched with pyrite, pyrrotine, calcium sulfide, and calcium sulfate; metal and alloys mainly containing Si, Al, Fe, C, etc. as well as reducing and sulfidizing complexes consisting of sulfides, oxides, and reducing substances (C, Me). Carbonaceous reducers, utilized individually or in mixture, are any known carbonaceous reducers. Degree of metal Me recovery is in accordance with conventional extraction equation.

EFFECT: increased degree of recovery of nickel from slags, reduced consumption of depleting agent, reduced power consumption and loss of sulfur into gas phase.

6 cl, 1 tbl

Description

The invention relates to the metallurgy of Nickel, in particular to the technology of depletion of slag mine smelting of oxidized Nickel ores (OHR). It can be useful for the depletion of slag and melts from the smelting of mainly nickel, copper, lead, antimony, tantalum and other metals.

Waste depletion methods are very numerous and well known. Widespread methods of flotation depletion of rich slag of Nickel and copper smelting in suspension [1]. However, the flotation method of depletion to the dump slag of mine smelting OHP is not applicable.

Widespread are also electric furnace depletion methods for rich slags of nickel and copper smelting in suspension [1, p.325-352; 2], as well as converter slag of nickel smelting [2].

Closest to the technical nature of our invention is a method of depleting slag from mine smelting OHP using mixtures of pyrites and coke, calcium sulfide and coke [2, p.277-279]. Here, the depletion of slag is carried out in one stage and the slag enters the depletion unit on the surface of the melt. Thus, the slag is depleted when the extraction number "n" is equal to one, the duration of the slag in the furnace is about 2 hours; maximum nickel extraction in matte (5.9-8.4% Ni) was 38%; specific energy consumption - 85-130 kWh / t of slag. The temperature of the slag is 1420-1480 ° C. Major disadvantages of this method are: low nickel recovery; obtaining nickel-poor matte, the use of pyrite and a high degree of desulfurization (> 50%); high consumption of lean mixture (2-6% by weight of slag).

The objective of the present invention is to increase the extraction of Nickel from slag during their depletion. Along with this, there is a decrease in the consumption of depleting agent, a decrease in the specific energy consumption, and a decrease in sulfur losses in the gas phase.

The problem is achieved in that in the method of depletion of slag for smelting oxidized nickel ores, including siphoning the smelting products from the smelter to the front furnace and treating the slag with a depleting agent containing sulfur-containing material and a carbon reducing agent, according to the invention, the slag is processed in countercurrent by loading depleting agent to the surface of the directed slag flow moving from the bottom up, while drops of depleting agent, falling from top to bottom, collect valuable the slag constituents, performing countercurrent movement, and the depleting agent consumption is maintained equal to 0.5-3.0% of the slag mass.

The processing of slag is carried out in a separate metallurgical unit, providing a continuous flow of slag from the smelter or furnace.

As a sulfur-containing depleting agent material, materials enriched with pyrite, pyrrhotite, calcium sulfide, calcium sulfate, metal reducing agents containing predominantly Fe, Si, Al can be used individually or in the presence of each other.

As depleting agents, reduction-sulfidizing complexes (BSC) of the systems: FeS ₂ —CaO— (CaCO ₃ ) —C; FeS ₂ -Fe ₂ O ₃ -C; FeS ₂ -Fe- (CaSO ₄ ) -C; FeS ₂ -Fe-CaO (CaCO ₃ ) -C.

As a carbon reducing agent, materials individually or mixed with each other are used, taken from the group consisting of metallurgical coke, sulphurous petroleum coke, semi-coke, coals, including brown and lean, anthracite, peat, peat coke.

Not only natural gypsum, but also technogenic wastes (phosphogypsum, fluorogypsum, etc.) can be used as CaSO ₄ carrier materials.

The technical result obtained by using the proposed technical solution is:

1. The depletion of slag mine smelting OHR using the principle of extraction with "n" (number of extractions), tending to infinity.

2. The extraction method of depletion of slag mine smelting can increase the extraction of Nickel from 87-90% (current state) to 95-97%.

3. The deep depletion of nickel smelting slags allows the mine smelting process to be carried out on almost any matte composition, up to Feinstein.

4. Slag impoverishment can be carried out without noticeable capital and operating costs.

5. The organization of mine smelting for mattes containing nickel much more than 12%, helps to reduce the consumption of sulfidization during melting, to reduce fuel and the transition of sulfur to the gas phase.

The essence of the invention is as follows. OHP smelting slag is deeply depleted in nickel and cobalt. This can be done by feeding the depleting agent to the slag melt exiting the shaft furnace in the front furnace or a separate smelting unit by means of countercurrent movement of the slag and depleting agent.

The degree of extraction of metals (Me) in this case is in agreement with the classical equation of extraction:

where (Me) _o and (Me) _n are Me concentrations in the initial and final slag, respectively;

L is the distribution coefficient Me between the slag and matte (ferronickel);

q is the matte mass per extraction;

Q is the mass of slag;

n is the number of extractions.

; концентрации никеля в исходном шлаке в 0,16%; значении q, равном 1,0, и L - 0,01, а также при использовании пирротина (FeS_1,14) в качестве обедняющего агента можно получить нижеследующие результаты:Theoretical calculations according to equation (1) showed that for values of "n" equal to 2, 3 and

; the concentration of Nickel in the original slag in 0.16%; a q value of 1.0 and L of 0.01, and also when using pyrrhotite (FeS _1.14 ) as a depleting agent, the following results can be obtained:

n = 1 n = 2 n = 3

n =

The Ni content in the waste slag,% 0.08 0.04 0.01 <0.001 The content of Ni in matte,% 8.0 12.0 15.0 16,0 Extraction of Ni,% fifty 67 94 99

An experimental verification of the above theoretical indicators was carried out in laboratory conditions (table).

In the experiments used slag mine smelting OHR at the Rezhsky Nickel plant composition,%: 0.13 Ni; 20.0 CaO; 12.4 MgO; 41.1 SiO ₂ ; 6.8 Al ₂ O ₃ ; pyrrhotite from the dissolution of pyrites of the Gaisky concentrator,%: 44.0 Fe, 50 S; petroleum coke of Perm oil refinery,%: 3.3 S; 7.8 volatile, 85 C, 0.3 ash.

Slag impoverishment was carried out at expenses (units): slag - 100; pyrrhotite - 1.0; petroleum coke - 0.01-0.3. The matte from the second extraction returned to depletion of the initial slag, and the matte from the third extraction returned to the head of the second extraction. Under these conditions, the following results were obtained:

n = 1 n = 2 n = 3 The Ni content in the waste slag,% 0.08 0.05 0,03 The content of Ni in matte,% 7.3 9.0 11.0 Extraction of Ni,% 38 61 77

Table
Examples of the method for the depletion of dump slags for smelting OHP (in terms of Q slag - 100 tons) Indicators / Examples No. of examples Prototype 1 2 3 4 5 6 7 8 nine 10 eleven 12 Ni concentration in 0.12 0.12 0.12 0.12 0.16 0.16 0.16 0.20 0.20 0.50 0.50 0.50 0.16 source slag The number of extractions "n" 1 2 3 3 2 3 3 3

^x)

^x) 3 3

1 The consumption of depleting agents, t: - pyrite (95% FeS ₂ ) 1,5 - coke 0.2 0.2 0.3 - pyrrhotite (FeS _1.14 ) 1,0 1,0 1,0 0.5 1,0 1,0 2.0 2.0 2.0 3.0 3,5 2.0 The concentration of Ni,%: - in final slag 0,070 0,042 0.024 0,048 0,055 0,032 0.014 <0.01 0.008 0.06 <0.01 0.08 - in matte 5.1 7.9 9.7 14,4 10.7 12.9 9.3 9.9 16,4 14.1 25.0 7.3 Extraction of Ni,% 42 66 80 60 66 80 93 99 98 99 99 fifty x) data for "n" →

- settlement

The above experimental data fully confirm the results of theoretical calculations.

We understand that the results of laboratory experiments in an industrial environment will undergo a certain adjustment in the direction of a possible decrease in the obtained indicators. Nevertheless, in laboratory conditions, we conducted experiments with q values equal to 0.5-3.0% of the mass of the initial slag, which showed that an increase in q above 3.0 is impractical (table, example 11), just as impractical and a decrease in q below 0.5 (example 4).

In conclusion, it must be said that any sulfidizing agent and / or metal reducing agent, as well as any combination of them with each other, can be used as a depleting agent. The use of metal reducing agents containing Si, Al, etc., is especially useful, since the depletion process is endothermic. In this case, the use of metal reducing agents makes it possible to completely or partially eliminate the need for heating the slag during its depletion.

For practical implementation, no radical reconstruction of existing equipment is necessary, since siphon production of smelting products that enter the front furnace, in which slag rises to the upper surface, is currently underway. Only some of the innovations in the design of the front furnace for the production of slag and the supply of a depleting agent to the furnace are needed.

There is no need to argue about the possibility of implementing the method in a freestanding furnace installation.

Thus, the data presented show the full feasibility of the proposed technology and indicate a solution to the problem.

Sources of information

1. Mechev V.V., Bystrov V.P., Tarasov A.V. and others. Autogenous processes in non-ferrous metallurgy. M .: Metallurgy, 1991, 414 p.

2. Reznik I.D., Ermakov G.P., Shneerson Y.M. Nickel. Volume 2. M.: Science and Technology, 2001.468 p.

Claims (6)

1. A method of depleting slag from smelting oxidized nickel ores, including siphoning the smelting products from the smelter to the front furnace and treating the slag with a depleting agent containing sulfur-containing material and a carbon reducing agent, characterized in that the slag is depleted in the depleting agent in countercurrent by loading the depleting agent on the surface of the directed slag flow moving from the bottom up, while the droplets of the depleting agent, falling from top to bottom, collect the valuable components of the slag, increasing countercurrent movement, and the consumption of depleting agent is maintained in an amount of 0.5-3.0% by weight of slag. 2. The method according to claim 1, characterized in that the processing of slag is carried out in a separate metallurgical unit with a continuous flow of slag from the smelter or furnace of the smelter. 3. The method according to claim 1 or 2, characterized in that as a sulfur-containing depleting agent material, individually or in the presence of each other, materials enriched with pyrite, pyrorotin, calcium sulfide, calcium sulfate, metal reducing agents containing mainly Fe, Si, Al are used . 4. The method according to any one of claims 1 and 2, characterized in that, as a depleting agent, reducing-sulfidizing complexes of FeS ₂ —CaO (CaCO ₃ ) —C systems are used; FeS ₂ -Fe ₂ O ₃ -C; FeS ₂ -Fe- (CaSO ₄ ) -C; FeS ₂ -Fe-CaO (CaCO ₃ ) -C. 5. The method according to any one of claims 1 to 4, characterized in that, as a carbonaceous reducing agent, individually or mixed with each other, materials taken from the group consisting of metallurgical coke, sulphurous petroleum coke, semi-coke, coals, anthracite, peat, peat coke. 6. The method according to claim 5, characterized in that brown and lean coals are used as coals.