RU2652278C1 - Method of processing copper produced converter slag - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to processing of copper produced converter slag. In bath furnace, together with converter slag, carbon-containing fuel and oxygen-containing gas, clinker of zinc production is supplied in amount of, determined by formula M_cl=(1.0÷2.0)(3Fe_cl+14C_cl)Fe_{converter slag}/100, where M_cl – the amount of clinker supplied, kg/t of converter slag, Fe_cl, – content of metallic iron in the clinker, wt%, C_cl – clinker carbon content, wt%, Fe_{converter slag} – iron content in converter slag, wt%.

EFFECT: increase in running time of furnace is provided by eliminating the formation of a layer of partially melted clinker or magnetite particles.

1 cl, 1 ex

Description

The invention relates to metallurgy, and in particular to methods of processing converter slag of copper production.

Copper production slag contains a significant amount of copper and is not dump slag. They must be processed in order to extract the valuable components contained in them.

Sometimes they are crushed, subjected to flotation, getting a copper concentrate, which is processed in pyrometallurgical units. In this case, an additional amount of copper is recovered, but a substantial part is still lost.

If converter slag is processed without pre-treatment, the degree of copper recovery can be increased. Converter slag of copper production can be processed in various pyrometallurgical units.

A known method of melting converter slag of copper production, including the supply of converter slag and calcium carbide (CaC ₂ ) as a reducing agent (patent of the Republic of Kazakhstan KZ No. 23261). This method allows the smelting of converter slag of copper production. However, its implementation requires the use of an expensive reducing agent - calcium carbide.

The closest in technical essence and the achieved result is a method for processing converter slag of copper production, including the supply of converter slag, carbon fuel, oxygen-containing gas, zinc clinker to the bathroom furnace (Republic of Kazakhstan KZ No. 1249). This method allows processing using zinc clinker as a cheaper reducing agent. The temperature in the furnace is ensured by the combustion of carbon fuel in an oxygen-containing gas. However, the application of this method does not provide long continuous operation without the formation of a layer of partially melted particles of clinker or magnetite in the furnace.

An object of the invention is to increase the duration of continuous operation of the furnace by eliminating the possibility of the formation of a layer of partially molten particles of clinker or magnetite.

To solve this problem, in a known method for processing converter slag of copper production, including feeding converter slag, carbon fuel, oxygen-containing gas and zinc clinker to a bathroom furnace, heating, melting converter slag and clinker, production of processed products according to the invention, the amount of clinker supplied determined by the formula

_Cl M = (1,0 ÷ 2,0) (3Fe _{cl cl} + 14C) Fe _SHL / 100,

where M _cl - the amount of clinker supplied, kg / t of converter slag; Fe _CL - the content of metallic iron in clinker,%; With _CL - the carbon content in clinker,%; Fe _SHL - iron content in the converter slag,%.

Typically, copper converter slag contains, wt.%: 1.2-3 Cu; 20-28 SiO ₂ ; 50-55 Fe. Iron in these slags is present in the form of two oxides: FeO and Fe ₃ O ₄ . The magnetite content can vary within a very wide range - from 10 to 28-30%.

Clinker zinc production contains, wt.%: Cu - 1-4; S - 3-8; SiO ₂ - 10-15; Fe - 20-30; C - 10-20. Iron in clinker is present in the form of oxides and metallic iron. The ratio of metallic iron to iron in oxides varies depending on the technology of zinc extraction and clinker formation. The carbon in the clinker is present as free carbon.

Carbon fuel and an oxygen-containing gas are supplied to a bathroom furnace with a temperature of 1250-1350 ° C. Carbon is oxidized by oxygen with heat. The amount of fuel and oxygen must be sufficient to maintain the temperature in the furnace. Also, converter slag of copper production and zinc clinker are fed into the furnace. Under the action of high temperature, a melt consisting of oxides and sulfides is formed from the supplied materials. Due to differences in the melt densities of oxides (usually 3.2-3.5 g / cm ³ ) and sulfides (usually 4.2-5.2 g / cm ³ ), they separate into two liquid phases: oxides form slag, sulfides - matte, located below the slag. As they accumulate, the slag and matte are removed from the furnace. Slag is sent to the dump, matte for copper production. The process can be conducted in continuous and batch mode.

It was experimentally established that if the amount of clinker supplied is less than that calculated by the formula

M _kl = 1,0 (3Fe _{cl cl} + 14C) Fe _SHL / 100,

a magnetite layer is formed in the furnace, which prevents continuous continuous operation of the furnace. That is, in this case, the reduction potential is insufficient in the furnace to restore the magnetite contained in the converter slag.

Magnetite at working process temperatures is present in the slag in the form of a solid phase with a density higher than the density of liquid slag and has a tendency to fall into a separate layer, cluttering the furnace working space.

Reducers with respect to converter slag magnetite are carbon and clinker metallic iron. In this case, magnetite in the furnace will accumulate and after some time the operation of the furnace will be disrupted due to the accumulation of magnetite in the furnace.

If the amount of clinker supplied is greater than that calculated by the formula

M _kl = 2,0 (3Fe _{cl cl} + 14C) Fe _SHL / 100,

a layer of partially molten clinker particles forms in the furnace, which also prevents the continuous operation of the furnace.

This is because the amount of iron and carbon contained in the clinker will be greater than that which can interact with converter slag magnetite, the reduction potential in the furnace will be such that the iron and carbon of clinker that do not react with converter slag magnetite accumulate, interfering with the continuous operation of the furnace, since they, at process temperatures, form a partially molten iron-carbon mass with a density higher than the density of liquid slag, which tends to form vaniyu semisolid separate layer accumulating in the furnace.

Examples.

4 tons per hour of converter slag of copper production, carbon fuel containing 1.5 tons per hour of carbon, oxygen-containing gas containing 2100 m ³ oxygen per hour and zinc clinker are continuously fed into the bathroom furnace.

Converter slag contains 30% iron.

Zinc clinker contains 30% metallic iron and 15% carbon.

If the amount of clinker production of zinc is less than M _kl = 1,0 (3Fe _{cl cl} + 14C) Fe _SHL / 100 = 1.25 (3 × 30 + 14 × 15) 30/100 = 90 kg per 1 ton of converter slag, i.e. less than 90 × 4 = 360 kg per hour, the duration of the furnace will be 6 days, after which a layer of magnetite is formed in the furnace, which prevents its further operation. It is necessary to stop the furnace, to remove magnetite from the furnace, so that the furnace can continue to work.

If the quantity of production of clinker zinc longer M _cl = 2,0 (3Fe _{cl cl} + 14C) Fe _SHL / 100 = 2.0 (3 × 30 + 14 × 15) 30/100 = 180 kg per 1 ton of converter slag, i.e. less than 180 × 4 = 720 kg per hour, the furnace will last for 8 days, after which a layer of partially melted clinker particles that does not react with magnetite forms in the furnace and impedes its further operation. It is necessary to stop the furnace, remove the layer of partially melted clinker particles from the furnace, so that the furnace can work further.

If the amount of zinc clinker production within _cells M = (1,0 ÷ 2,0) (3Fe _{cl cl} + 14C) Fe _SHL / 100 = (1,0 ÷ 2,0) (3 × 30 + 14 × 15) 30 / 100 = 90 ÷ 180 kg per 1 ton of converter slag, i.e. from 360 to 720 kg per hour, the furnace will last for 90 days without the formation of a layer of magnetite or partially melted clinker particles that impede its further operation. The duration of continuous operation of the furnace in this case is determined by production needs.

Claims (6)

A method of processing converter slag of copper production, including supplying converter slag of copper production, carbon fuel, oxygen-containing gas, zinc clinker to a bathroom furnace, heating, melting converter slag and clinker, production of processing products, characterized in that the amount of clinker is determined by the formula

, where M _cl - the amount of clinker supplied, kg / t of converter slag; Fe _CL - the content of metallic iron in clinker, wt.%; With _CL - the carbon content in clinker, wt.%; Fe _sl - the iron content in the converter slag, wt.%.