RU2441082C1 - Method of producing nickel matte - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: burden containing pelletised oxidised nickel-containing or and reducing fuel are loaded into shaft furnace. Then, reducing-sulphiding smelting is carried out using coke reduction agent as fuel. Note here that said coke is produced by carbonising the burden containing 5 to 100% of product, the yield of volatile substances making some 14-25%, obtained by delayed low-temperature carbonisation of heavy oil residues.

EFFECT: reduced fuel consumption higher smelting rate of nickel-containing stock, reduced nickel content in slug.

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Description

The invention relates to metallurgy, and in particular to methods for processing oxidized nickel ores.

A known method of producing nickel matte according to the patent of the Russian Federation No. 2187568, in which metallurgical coke and high-quality coal with a yield of volatiles of not more than 14% are used as a reducing agent.

The disadvantage of this method is the increased nickel content in the slag and the increased consumption of coke.

A known method of producing nickel matte according to the patent of the Russian Federation No. 2184162, selected as a prototype, comprising loading into a shaft furnace a mixture containing agglomerated oxidized nickel-containing ore and a reducing agent, sulphiding reduction smelting using metallurgical and lump petroleum coke as a reducing agent, taken in a ratio of respectively 40-95: 60-5 wt.%.

The disadvantage of the method chosen for the prototype is the increased consumption of coke during melting and a reduced specific melt, high ash content of metallurgical coke, reduced coke fineness.

The technical result is a reduction in fuel consumption and an increase in the melt of oxidized nickel ore due to an increase in the calorific value and a decrease in the reactivity of coke, a decrease in the nickel content in slags due to the interaction of coke having a high sulfur content with melt nickel and its conversion to sulfur sulfide, which transforms into matte.

The technical result is achieved by the fact that in the method for producing nickel matte, which includes loading a charge into a shaft furnace containing agglomerated oxidized nickel ore and a reducing fuel, reducing sulfiding smelting using coke as a reducing fuel, coke resulting from coking is used according to the invention charge containing the product with a yield of volatiles from 14 to 25% in the amount of (5-100) wt.%, obtained by delayed semi-coking of heavy oil residues.

Coke obtained during the coking of petroleum coke with a yield of volatile substances from 14 to 25% enriched in the process of delayed coking with high molecular weight volatile substances (table 2, charge 7) differs from petroleum coke obtained by calcining petroleum coke with volatiles 8-10 % (up to 14%), for example in ring or rotary drum furnaces, with higher strength, increased coarseness of coke pieces (D mm), reduced reactivity (CRI), increased post-reaction strength (CSR). Thus, it is a special coke with improved properties. Additives of such a semicoke to coal blends (table 2, blends 1-6) improve the quality of the obtained coke.

Coke obtained from a mixture containing a product (obtained by delayed semi-coking of heavy oil residues) with a yield of volatiles from 14 to 25% in an amount of 5-100 wt.%, Has the properties shown in table 1.

For convenience of presentation, the product with a yield of volatile substances from 14 to 25%, obtained by the method of delayed semi-coking of heavy oil residues, hereinafter referred to as additive DC.

The coal part of the charge is given as one of the special cases for example. Other components and combinations of charges are possible.

Moreover, table 2 shows examples of the charges, which are indicated in table 1 as the charge 1,2,3,4,5,6,7.

Table 1 Charge components Component Quality Score Coke Quality Indicators A ^d ,% V ^daf ,% S ^d ,% Ivsp. A ^d ,% V ^daf ,% S ^d ,% CRI CSR Cbs GZH, GZHO 7.69 38.30 0.72 129.0 GJ + F 8.51 36.31 0.61 139.0 KO + OS 8.71 22.05 0.49 8.0 OS + KS 7.62 17.72 0.50 10.0 KO + KS 9.39 20.11 0.72 7.0 K + KS 10.3 26.09 0.43 7.0 Coking additive (DK) 1.10 17.70 3.60 10.0 charge 1 8.47 28.77 0.54 7.0 12.36 1,04 0.49 36.3 47.6 83.6 charge 2 7.98 28.19 0.82 10.0 11.47 0.85 0.77 33.7 52.1 83.0 charge 3 7.64 27.1 0.95 9.0 10.96 0.98 1.10 31.9 58.5 85.3 charge 4 7.34 26.82 1.29 8.0 10.25 0.89 1.21 31.3 57.8 85.0 charge 5 6.13 25.0 1,50 8.0 8.35 0.86 1.85 30.1 60.3 86.2 charge 6 4.76 24.41 2.09 9.0 5.85 0.87 2.25 27.8 65.1 86.4 charge 7 1.10 17.70 3.60 10 1.35 0.75 4.2 25.1 72.3 86.6

Example 8: The charge 8 is composed of 50% petroleum coke with a yield of volatiles of 14.2% and 50% petroleum coke with a yield of volatiles of 24.8%, while coke was obtained with CSR = 70.5%, CRI = 23, 8%. When tested in a heat, results similar to those according to example 7 are obtained.

Indicator A ^d - coke ash in the dry state; V ^daf is the yield of volatile substances in the dry ashless state of coke; S is the sulfur content of the dry state of coke;

Ivsp. - expansion index; CRI - an indicator of the reactivity of coke; CSR is an indicator of the post-reaction strength of coke.

table 2 Charge components Charge options,% one 2 3 four 5 6 7 GZH, GZHO 33.0 30,0 28.7 27.5 0 15.0 0 GJ + F 12.0 10.9 10,4 10.0 20,0 15.0 0 KO + OS 10.0 9.1 8.7 8.3 14.0 0 0 OS + KS 20,0 18.2 17.4 16.7 20,0 10.0 0 KO + KS 10.0 9.1 8.7 8.3 16,0 0 0 K + KS 15.0 13.6 13.1 12.5 0 10.0 0 Coking additive (DK) 0 9.1 13.0 16.7 30,0 50,0 100.0 Total: 100.0 100.0 100.0 100.0 100.0 100.0 100.0

Tests (the results are shown in table 1), conducted on a Nikolaev furnace, show that the post-reaction strength of coke from a charge with DC is higher than that of coke without an additive. The dependence of coke CSR on the content of the additive in the charge is close to the logarithmic: logCSR = A + BlgC, where C is the content of the DC additive in the charge.

Petroleum coke has several advantages over metallurgical one - it is not deficient, inexpensive, and has low ash content (less than 0.5 wt.%), While the ash content of metallurgical coke is 11-13 wt.%. In addition, there are great prospects for an increase in the production of petroleum coke in connection with the inevitable growth in the production of advanced oil refining, as well as in the special production of additives for coking DK.

Conducted by the authors of the present invention, industrial sulphiding reduction smelting of oxidized nickel ores with the replacement of metallurgical coke by coke from coal blends with the addition of DC in an amount of 5 to 100 wt.% Showed the possibility of reducing coke consumption during the smelting of oxidized nickel ores. Therefore, when using coke from blends with the addition of DC, nickel losses are reduced (the nickel content in the slag is reduced).

In addition, due to the reduction in coke ash and, therefore, the reduction of fluxes for slagging of coke ash, the amount of slag and nickel loss with this part of non-formed slag are also reduced.

According to the statistics of the inventors, it was found that the consumption of coke is larger than 40 mm when smelting nickel sinter from oxidized nickel ores in shaft furnaces by 15% lower compared to the consumption of coke larger than 25 mm. Therefore, the consumption of larger coke, ceteris paribus, should be reduced.

Melting using coke with the addition of DC should be accompanied by maintaining the previously used loading conditions (spike size) with more complete combustion (using chemical potential) due to the reduction in spike height, lowering the surface of pieces of coke, and increasing gas permeability.

The proposed method was tested in the reduction-sulphiding smelting of oxidized nickel ores in industrial shaft furnaces with a height of 5 m, a length of 14.5 m, a width in the tuyere region of ~ 1.4 m, and a cross-sectional area in the tuyere region of ~ 20 m ² . The furnaces had a remote horn of Petrov.

The authors conducted tests and determined the indicators of reduction-sulphiding smelting according to the claimed method with coke from the charge with the content of the additive DC in the amount of from 5 to 100 wt.%. An air blast was used.

As the ore part of the charge, briquettes of 90 × 50 × 40 mm in size and ore “okat” with pieces larger than 30 mm were used. The average chemical composition of the ore part of the charge, wt.% Was: Ni - 1.08; Co - 0.022; SiO ₂ 43.1; MgO - 15.2; CuO - 1.5; Fe ₂ O ₃ - 18.0; Al ₂ O ₃ - 7.5.

Pyrite was used as a sulfidizing agent in an amount of 8–9% of the ore part of the charge, and limestone in an amount of 14–18% was used as a flux.

Technical indicators characterizing coke from different blends are given in table 1.

The furnaces were loaded with a single charge using electric vehicles half the length of the furnace in the sequence: fuel (coke), limestone, sulphidizer, ore materials (“open”, briquettes). Loading was carried out when the electric car stopped at half the length of the furnace.

The test results are shown in table 3.

Table 3 one 2 3 four 5 6 7 8 9 10 eleven 12 13 fourteen fifteen one Metallurgical coke over 40 mm 30,0 one hundred 12.65 0.25 0.43 0,066 19.64 0,120 0.37 28.11 0 105 0 2 Charge coke with 50% DC 27.0 one hundred 12.87 0.25 0.39 0.059 19.98 0,110 0.39 30.15 7.26 110 10 3 Charge coke with 50% DC 27.0 fifty 12.05 0.23 0.37 0.058 20.60 0,083 0.40 30.45 8.34 145 10 Petroleum coke with volatile up to 14% fifty four Charge coke with 50% DC 27.0 80 11.95 0.23 0.40 0,057 20.45 0,084 0.41 30.11 7.36 142 10 Petroleum coke with volatile up to 14% twenty 5 Charge coke with 50% DC 27.0 70 11.88 0.24 0.39 0,060 20.35 0,085 0.40 29.95 6.55 140 10 AO brand coal thirty 6 Charge coke with 5% DC 30,0 one hundred 12.60 0.25 0.43 0,066 19.5 0.12 0.37 28,20 0.32 one hundred 0.5 7 Charge coke with 15% DC 29.5 one hundred 12.60 0.25 0.43 0,068 19.9 0.12 0.37 28.75 2,34 one hundred 1,67 8 Batch coke with 100% DC 27 one hundred 11.8 0.24 0.39 0,060 20.45 0,085 0.40 30,0 8.50 145 12 9 Metallurgical coke over 40 mm 28.5 one hundred 12.85 0.23 0.35 0,060 19.13 0.18 0.37 29.5 0 71.39 0 10 Coal charge coke with 50% DC 26.5 one hundred 12.95 0.25 0.37 0,045 19.85 0.15 0.39 31.6 7.0 86.33 7.0 eleven Coal charge metallurgical coke larger than 40 mm 21.0 one hundred 12.75 0.27 0.39 0.61 19,20 0.17 0.39 43.1 0 75 0 12 Coal charge coke with 50% DC 19.8 one hundred 12.90 0.27 0.40 0.55 20.5 0.14 0.40 46.8 8.6 92 15.0

Table 3 column names:

1 - “No."

2 - Type of coke

3 - Coke consumption in technology (in%) to the ore part of the charge (total coke consumption),%

4 - Share in the total consumption of coke,%

5 - content in matte Ni,%

6 - content in matte Co,%

7 - content in matte Cu,%

8 - content in matte As,%

9 - matte content S

10 - content in the slag Ni,%

11 - content in slag S,%

12 - specific melt, t / m ² * day

13 - increase in penetration,%

14 - ratio Ninstein / Nishlag

15 - reduction in coke consumption,% of the total coke consumption.

Examples 9 and 10 were carried out during the melting of briquettes from oxidized nickel ores with a blast enriched with oxygen up to 24%, and Examples 11 and 12 - during smelting and using a blast enriched with oxygen up to 24%. The agglomerate according to examples No. 11, 12 is characterized by a content of 0.8-1% Ni; 0.025% Co.

The results of the tests showed that when a part of metallurgical coke is replaced with coke from a mixture with the addition of DC, there is a reduction in coke consumption and an increase in melt compared to metallurgical coke.

Reducing the consumption of coke obtained from coal-containing blends with the addition of DC, for two reasons. Firstly, coke with the addition of DC is lower in ash content, and secondly, the fineness of coke pieces is higher. The ash index is shown in Table 1. An industrial inspection of the production of coke from a mixture with a content of DC in the amount of 5 to 100 wt.% Showed that the average size of pieces of such coke with a content of DC in the amount of 40% is 90 mm. The average size of metallurgical coke is 55-65 mm. This contributes to a more complete burning of coke.

In addition, coke from mixtures with the addition of DC has an increased density up to 1.25 g / cm ³ , versus 1.00 g / cm for coke from mixtures without the addition of DC, as well as a higher true density of 1.830-1.840 g / cm ³ against 1.790-1.815 g / cm ³ for coke from the charge without the addition of DC, which leads to a decrease in the reactivity of coke.

The consumption of large coke during the layered combustion process in low shaft furnaces of the cupola type is always lower at the same temperature conditions and rational loading technology due to more complete combustion of coke carbon (more complete use of the chemical potential, i.e., afterburning of CO). At the same time, environmental conditions are improved by reducing fuel consumption and its more complete chemical combustion (reducing emissions of CO and flue gases). The high sulfur content of coke is used in smelting to produce nickel matte.

It should also be noted that with the increase in the content of DC additives in the coking charge, the cost of coke decreases, therefore, the production process of nickel matte is cheaper.

Thus, the use of coke from mixtures with the addition of coking DC in place of metallurgical coke leads to a decrease in the total consumption of coke upon receipt of nickel matte. Compared to petroleum coke, the yield of volatile substances in flue gases is reduced, the ecology is improved, and the operation of filters to remove dust is simplified.

A decrease in coke consumption is also accompanied by an improvement in the ecology of the process, since leads to lower emissions of the amount of flue gases.

Claims (1)

A method for producing nickel matte, comprising loading a charge into a shaft furnace containing agglomerated oxidized nickel-containing ore and a reducing fuel, and sulphiding reduction smelting using coke as a reducing fuel, characterized in that coke obtained by coking is used as coke charge containing 5-100 wt.% product with a yield of volatiles from 14 to 25%, obtained by delayed semi-coking of heavy oil residues.