SU1573040A1 - Method of processing tin materials containing arsenic - Google Patents

Abstract

The invention relates to the processing of tin materials containing mouse. The aim of the invention is to increase the recovery of non-ferrous metals. Tinned materials together with reducing agent, fluxes and lead-containing materials are melted to produce a lead-tin alloy and a ferrous alloy. In loading, the ratio of iron and mouse is supported (2–7): 1. Melting and reduction of iron with conversion into an alloy is carried out until the iron content in the slag is 0.5–10%. 1 tab.

Description

The invention relates to the field of non-ferrous metallurgy and is intended for processing tin materials, such as fuming sublimates, to obtain lead-tin alloys and preliminary refining from arsenic.

The aim of the invention is to increase the recovery of non-ferrous metals.

The method is carried out as follows.

A smelting unit, such as an electric furnace, is charged with a residual slag bath consisting of fuming sublimates, a reducing agent, fluxes, including an iron-containing reagent, such as pyrite cinder, in an amount that provides the required ratio of iron and mouse in the load. Then lead materials are loaded:

secondary lead or metallic lead for the production of lead-tin alloys. If lead is not added, a high content of tin leads to its increased content in the alloy and transition to gartling. The amount of reducing agent is determined by the content of non-ferrous metal oxides, arsenic and iron B loading and is selected with an excess of 15–20% of stoichiometrically necessary for their reduction to metals. After the melting, reduction, and settling of the melting products are completed, the draft alloy and garth are released from the furnace. Slag is allowed to the required level only if the level of the melt does not allow loading in subsequent melts. Since the content of slag-forming in fuming-air

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The rails are low, the number of fluxes to adjust the composition of the slag is small. The need to release slag after each melting reduces the loss of metals with slags. Obtaining toxins of a given composition and a given amount of garting simplifies smelting technology.

Example, Melting is subjected to lead-tin fuming-sublimation composition, wt.%: Tin 28,4; lead 29.6; mouse to 2.3; silica 8.3; iron 1.5; calcium oxide 0.3; others - the rest. As a reducing agent, cobalt krupnost + 3-20 mm with a carbon content of 75% is used. Melting is carried out in an electric furnace according to a known method and the proposed method. When smelting by a known method, a bath of granulated slag is introduced into the composition, wt%; nitrous oxide 32.6; silica 32.8; calcium oxide 8.6; tin 0.1; the rest is other. A sublimate is charged to the slag bath, coking at the rate of 25% of the excess of the stoichiometrically necessary for the reduction of non-ferrous metals, arsenic and iron parts. To provide a ratio of calcium oxide and iron to silica not lower than 1: 1 for smelting the charge from the pyrite calcine, then lead-containing materials are loaded. In their quality in all experiments using secondary lead raw materials containing 75., 4% lead and not containing tin. The ratio of the amount of lead to tin sublimates and secondary raw materials is 6.6 in all experiments: After the end of smelting, the slag is discharged before leaving the primary bath for the next smelting. Gartling and draft alloy are completely released from the furnace. Sublimates from the furnace are caught in a bag filter and taken into account when drawing up the material balance.

When smelting, according to the proposed method, sublimates of the same composition are loaded onto a bath of previously deposited iron-free slag containing, in wt.%: Sodium oxide 2056; calcium oxide 23.5; silica 42.4; the rest is other. Together with sublimates and a coking regenerator, the glands containing the reagent, the pyrite cinder containing 54.7 wt% of iron, bind;

the lead-containing recyclables. By

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the completion of smelting is the production of rough metal and gartling. When loading sublimates, subsequent melts with fuming sublimates serve small amounts of fluxes, soda, and quicklime to maintain the composition of the slag. Slag in subsequent melts is partially discharged if the level of its bath rises to the limits that prevent the loading of the same number of sublimates per smelting.

The results of the heats are presented in the table, where experiment 1 was carried out according to a known method, experiments 2–4 - according to the proposed and experiments 5–7 - with beyond indicators.

Analysis of the table dacha shows that the best results are achieved when working on the proposed method. An increase in the ratio of the amount of iron to the amount of mouse in the load leads to a decrease in the content of the mouse in the draft alloy. At the same time, the yield of hartlings increases and the extraction of non-ferrous metals somewhat decreases, remaining, however, higher than with the known method. When operating according to the proposed method, the temperature of the slag melt is lower than that by the known method, since the slag composition is selected as low-melting (Hp /, -1,180 ° C), it is 1200-S250 against 1300-1350 ° C. Therefore, the sublimation of tin and lead during smelting decreased 1.3-1.5 times. The amount of slag produced during the smelting time decreased by 3.5-3.8 times, which also increases the direct recovery.

Going beyond the proposed ratio of the amount of iron to the amount of mouse leads to a decrease in the recovery of non-ferrous metals due to an increase in the yield of gartling (work above the upper limit) or an increase in the content of the mouse in the draft alloy (work below the lower limit). Increasing the iron content in the final slag beyond the proposed limits due to its low degree of reduction results in a decrease in the amount of gartling, which

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increase in mouse content in the draft alloy. At the same time, the content of lead and tin in the slag increases by 0.3-0.4%, which leads to a drop in the extraction of non-ferrous metals into the alloy

(experiments 3 and 7). A decrease in the iron content in the slag below the proposed limits does not lead to an increase in the extraction of non-ferrous metals, but the consumption of the reducing agent increases sharply.

Claims (2)

1. A method of processing tin materials containing mouse, including their smelting with reducing agent, flux and lead-containing materials, characterized in that, in order to increase the extraction of non-ferrous metals, the process is carried out with the addition of iron-containing flux at the ratio of iron and mouse in the load (2-7): 1 and loading of the reducing agent with an excess of 15-20% of stoichiometry amount for reducing oxides of non-ferrous metals, arsenic and iron to metals. 2. The method according to p. 1, characterized in that as the iron-containing flux use pyrite. a candle ... Soda and lime for adjusting the composition of slag1