JPS61174341A - Method for refining slime produced by electrolysis of copper - Google Patents

Abstract

PURPOSE:To obtain high-grade rich lead in a high yield by adding a siliceous flux, a lime-base flux and a small amount of a carbonaceous reducing agent to slime produced by the electrolysis of copper and by melting them by heating to transfer base metals in the slime into formed slag. CONSTITUTION:A siliceous flux, a lime-base flux and a carbonaceous reducing agent such as coke are added to slime produced by the electrolysis of copper and roasted. The amount of the reducing agent added is 1-4% of the amount of the slime. They are melted by heating to transfer most of base metals in the slime into formed slag. After the reduction is finished, the formed slag is separated and solidified. By this method, slag having a high lead content and rich lead having a high silver content are obtd. in high yields. The rich lead is sent to the next silver separating stage.

Description

Detailed Description of the Invention (Industrial Field) The present invention involves adding fluxes such as lime, silica sand, etc. and reducing agents such as coke and coal to copper electrolytic slime, heating and dissolving the mixture, and removing lead, aluminum, bismuth, etc. This invention relates to a method for smelting copper electrolytic slime, which turns most of it into slag and produces noble lead with a high silver content.

(Prior art and its problems) In addition to precious metals such as gold and silver, copper electrolytic slime also contains copper,
Contains selenium, tellurium, lead, antimony, bismuth, arsenic 2, etc. Among these, copper is removed by leaching with sulfuric acid while performing air oxidation, or by leaching with sulfuric acid after oxidative roasting. This is sometimes referred to as decoppered slime to distinguish it from the slime produced in the electrolytic process, but hereinafter copper electrolytic slime will be simply referred to as slime.

Although various different methods have been proposed for the treatment process of copper electrolytic slime, the following is a general method.

(1) Performing oxidation roasting or sulfation roasting to volatilize and remove selenium, (2) Adding flux and a reducing agent and heating and dissolving the lead,
Slagt, gold containing antimony and bismuth.

(3) Further, a step of oxidizing and removing lead, cerium, tellurium, copper, etc. in the noble lead to produce crude silver called metal. It is.

In the second step of these processes, it is desirable to use as much reducing agent as possible to achieve complete reduction in order to minimize the loss of lead metals to the slag. It is unsuitable because most of the precious lead is reduced and the silver quality of the precious lead is significantly reduced.

As a result, in the third step, a large amount of lead has to be oxidized and separated as slag, which lengthens the reaction time, and the resulting slag still contains high concentrations of gold and silver. ing. Therefore, reprocessing is necessary, which impedes the efficient operation of the process as a whole.

As one of the improvement measures to enable efficient operation of the above process, a method for separating lead sulfate from slime by flotation has been proposed (Japanese Patent Application Laid-open No. 123428/1982). This method is very effective when the lead content of the slime is high, and approximately i of the lead content can be separated as tailings mainly composed of lead sulfate. However, it is not very effective if the lead content of the slime is not very high.

In addition, the lead in the slime was removed by alkylena ami.
For example, diethylene triamine
(U.S. Patent/164.283.
224) and a method of leaching with acetate (Japanese Unexamined Patent Publication No. 149.437/1983), etc. have been proposed.

These wet processes have the advantage of recovering lead as carbonates and other compounds;

This method has the problem of large costs due to loss and treatment of washing water.

Furthermore, a method has also been proposed in which a flux such as soda ash is added to the unroasted slime and the slime is heated in a non-reducing atmosphere to turn lead into slag and produce noble lead containing selenium, tellurium, silver, etc. (Special Publication No. 57-23735).

Compared to the conventional method of roasting slime to remove selenium, this method uses soda ash and The amount of reagents such as saltpeter used is large, and the reaction time is also long. The problem with using soda-based flux in the slime melting process is that the refractory material in the furnace is consumed considerably.

(Object of the Invention) The object of the present invention is to solve the above-mentioned problems of the prior art and to provide a method for smelting copper electrolytic slime that makes it possible to obtain noble lead of higher quality than copper electrolytic slime in a higher yield. It is on offer.

(Structure of the Invention) That is, according to the present invention, basically, the copper electrolytic slime is decoppered or after decoppered, further roasted to remove selenium, flux and a reducing agent are added thereto, and then heated, In the method for smelting copper electrolytic slime, the copper electrolytic slime is added with a reducing agent consisting of 72x consisting of siliceous flux and lime flux and a carbonaceous substance in the range of 1 to 4 times of the copper electrolytic slime. is added and heated to melt the copper electrolytic slime and transfer a substantial portion of the base metal in the copper electrolytic slime into slag, producing high lead grade slag and high silver grade yellow lead. A method for smelting copper electrolytic slime is obtained.

In addition to the above-mentioned basic configuration, the present invention further includes solidifying and pulverizing the generated slag, flotating it, and recovering it as a concentrate in which gold, silver, ceres/tellurium in the slag is concentrated. However, by repeating this concentrate in the above-mentioned melting process, it becomes possible to obtain noble lead with high silver grade at a high yield.

Next, the present invention will be explained in further detail.

Copper electrolytic slime usually contains 1 to 3 parts of tellurium and 10 to 50 parts of tellurium.
Contains the person in charge. If the selenium content is low, it is possible to directly heat and melt without roasting to remove selenium, but if the selenium content is high, the slime must first be oxidized or sulfated roasted. Removing the selenium contained by calcination makes it easier to operate in subsequent steps. This roasting may be carried out by any method, but the roasting method described in Japanese Patent Publication No. 49-30328 will be described as follows.

A so-called short rotary furnace is used as this roasting furnace. This furnace has a preheated furnace temperature of 15 tons! While charging the dissolved slime, raise the temperature to 800-9.
Roasting is carried out while maintaining the temperature at 00°C and rotating the furnace. After charging one char of slime, there are still 5
Burning is performed for about 5 hours to volatilize 80 to 90 tons of selenium contained.

The volatilized selenium is recovered by scrubbing the selenium-containing exhaust gas with an aqueous sodium hydroxide solution.

+1 in the furnace at this stage! Since the i-grilled slime is maintained at about 900°C, additionally charged in-process materials such as smoke ashes, slag, etc., flux made of limestone, silica, etc., and a small amount of coke are added to heat the slime to a temperature of 1) 00°C to 1250°C. Heat to ℃ to dissolve. The furnace continues to rotate to promote melting. When these charges are completely melted and the reduction reaction is completed, the rotation of the furnace is stopped, the slag and yellow lead are separated by a settling ring, the furnace is tilted, and the slag is extracted into a slag ladle and solidified. The yellow lead is extracted into a precious lead ladle and sent to the next silvering process.

When heating and melting the slime, there are two methods: using soda flax and producing iron-silicate base slag, but the former method has the drawbacks that the slag is highly corrosive and the life of the furnace material is short. The latter method had the disadvantage of producing a large amount of slag due to the addition of iron.

In the basic process of the present invention, which involves melting copper electrolytic slime and producing high lead grade slag and high silver grade yellow lead, a silicate-based flux is added to promote lead slagging. . At this time, scrap iron is not added in order to reduce the amount of slag produced. That is, in the conventional method, the lead content in the slag was in the range of 25 to 30%, but in the method of the present invention, the amount of the reducing agent added is minimized in order to increase the lead content in the slag to 35 to 45%. That is, it is necessary to add coke or coal in an amount of 1 to 4 times the roasted slime. If the amount of reducing agent added is 1% by weight, the effect of addition will be significantly reduced, and if it exceeds 4% by weight,
No improvement in effectiveness can be seen anymore, and it becomes disadvantageous in terms of cost. The main slag components other than lead are silica (SiOx) and lime (Cab), but the slag composition is Si0.8~
15L4°CaO ranges from 1 to 3 degrees. Since the slime contains a small amount of SiO, the amount of flux added should be enough to produce the above-mentioned slag. In the case of a slime containing about 2.5 parts of SiO, a slag having the above target composition can be obtained by adding 3 parts of coke, 1 part of silica sand, 9 parts of limestone, and 5.4 parts. At this time, the amount of silver in the noble lead obtained is 50 to 6 (l). There is a positive correlation between Pbl in the slag and Ag% in the noble lead as shown in Figure 1, and If slag is generated, the quality of the scissors in noble lead will be improved.However, at the same time, the loss of bond to slag will also increase.Figure 2 shows the distribution ratio between button slag/precious lead and silver in noble lead. Conceptually shows the relationship with dignity.

Precious lead is processed in the next silver separation process to become coarse silver. The composition of noble lead is 4-10% lead other than the above 50-60% silver.
%, selenium 10-15%, tellurium 1(1-20%, copper 5%)
~6chi. In noble lead with a silver grade of 40 cm, the lead content is approximately 20 cm.
The lead content in high-silver yellow lead is significantly lower than that of ~25%, indicating that the slagging of lead during the melting process is increased accordingly. Since the amount of lead to be oxidized during the silver separation process is small, the reaction time of the silver separation process is also shortened.

As a result of the improved lead quality, the slag production rate is 65 to 70% higher than the conventional 25% Pb slag production.
It is only %. On the other hand, the content of silver etc. is slightly high,
g O, 5 to 3%, S e O, 5 to 1.5 %, and 'l'el to 4 %. Furthermore, compared to the conventional method,
Since the amount of slag produced is small, these contents do not increase significantly, so it can be sent as is to the lead smelting process.

Next, in the process following the basic process of the method of the present invention, that is, in the process of making useful the high lead grade slag and high lead grade precious lead produced in the basic process, the slag is solidified, pulverized, and suspended. By concentrating and recovering gold, silver, selenium, and tellurium as concentrates through ore beneficiation, repeating the above-mentioned melting process and treating them simultaneously with slime, the yield of the above components can be increased. The finer the particle size of the pulverized slag, the better the beneficiation result, but -xoo micro 7 or so is sufficient.

Slurry 1) 1 degree 1o o -20og/43. P
H8-10, pine oil was used as a foaming agent, and DTP-8 manufactured by Nippon Koyaku Yakuhin Co., Ltd., for example, was used as a collecting agent. In one case, A u O, 07fA, Ag
In the case of slag with ratio 2.2, 17% 5eO, 1.8% Te, and 44% Pb, approximately 151 concentrates of Au+Ag1O~15 are obtained from the slag, and tilling is Au (0,001%).
, Ag0.3-0.35%, Se0.13%, Ta0.
It decreased to about 55%. The yield is approximately 99% Au, approximately 90% Ag, 85% Se, and 751% Te.

The above pine oil and DTP-8 (trade name) are as follows. The main component of pine oil is terpineol, and what is its structural formula? It is H3. On the other hand, the main component of DTP-8 is dithiophosphate, and its structural formula is. The lead migration rate to tilling is about 904,
This tilling can be sent to a lead smelter to further recover the lead and small amounts of remaining gold and silver. The concentrate is repeated in the slime melting process.

Next, the present invention will be explained in more detail with reference to examples, but the scope of the present invention is not limited by the following examples.

Example 1 3.2 tons of slime A and 22 tons of slime B shown in Table 1 were oxidized and roasted at 900°C to remove selenium.Estimated removal rate: 8
5 h), then additionally charged the in-process repeated materials shown in Table 1, 160 kg of coke, 240 II limestone, and 45 kg of silica, and while rotating the furnace, 1) 50 to 1200 @
GK was heated and dissolved. The solution was dissolved in about 10 hours and the reaction was completed, so it was left to stand for about 1 hour and the slag and noble lead were extracted. The quality of these products is shown in Table 1. The estimated amount of production is also listed in Table 2. The slag had a pb content of 42%, a sb content of about 41%, and a Bi content of about 1.5%. −
The precious lead was treated in a silver separation process according to a conventional method, and the treatment time was shortened by about 60% compared to the conventional case of noble lead containing 40% Ag. In addition, the amount of dust and soda slag generated during the silver separation process was reduced to about 60 parts in the conventional method, and about 30 parts in the conventional method.

Example 2 The raw materials shown in Table 1 were roasted, and 80 kg of recycled material and coke were produced.
2. 240 kg of limestone and 40 ml of silica sand were additionally charged and heated and melted. The composition of the output is shown in Table 2.

Table 2 Product Composition (Example 2) The yellow lead was further processed in a silver separation process. The slag was solidified and subjected to flotation treatment. The grinding particle size is 1100 microns and 80 inches.
Table 3 shows the results of flotation using slurry concentration of 160 g, pH of 8 to 10, pine oil as a foaming agent, and DTP-8 as a collection agent.

The amount of concentrate produced is about 15 times the amount of treated slag, and the transfer rate of lead to the tilling that is repeated in the slime melting process is about 90 times, and the concentrate is sent to lead smelting. Money,
Since more than 90 silver is separated, the yield in the slime process is extremely high. The transfer rate of antimony and bismuth to tilling was almost the same as that of lead, and was 85 to 90.

Table 3 Slag Flotation Treatment Results (Effects of the Invention) By adopting the above configuration, the present invention can achieve the following effects.

(1) Most of the lead, antimono, and bismuth in the slime can be converted into slag, which improves the quality of silver in noble lead and improves the efficiency of the post-processing process. Significantly improved. In addition, the amount of intermediates produced in the dividing process such as Mitsuda is significantly reduced, so
The load on the slime melting process is also reduced.

(2) By using lime quality flux in combination,
Can operate at relatively low temperatures. The corrosion of bricks by slag, which is a problem when using soda-based flux, is significantly alleviated because silica-based and lime-based fluxes are used together, extending the life of the furnace and increasing its operating rate.

(Since the lead quality of the 31 slag can be increased to 35 to 45 inches, the amount of slag produced is reduced to 65 to 70 inches compared to the conventional case where the lead quality of the slag is about 25 inches.

Therefore, the cost of reprocessing the slag is reduced.

(4) Although the loss of gold, silver, selenium, and tellurium to slag tends to increase slightly compared to conventional methods, by solidifying and pulverizing the slag and performing flotation treatment, 75% of these components can be removed. 99% can be concentrated and recovered as concentrate. The transfer rate of lead to tilling is about 90%, and even if the flotation concentrate is mixed in the slime melting process, the amount of slag produced is only slightly increased.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the relationship between the lead quality of slag and the silver quality of noble lead, and FIG. 2 is a diagram showing the distribution ratio of silver to slag and yellow lead.

Claims (6)

[Claims] (1) In a method for smelting copper electrolytic slime, the copper electrolytic slime is decoppered or after decoppering, further roasted to remove selenium, flux and a reducing agent are added thereto, and then heated and melted. A flux consisting of a siliceous flux and a lime flux and a reducing agent consisting of a carbonaceous substance in the range of 1 to 4% of the copper electrolytic slime are added to the electrolytic slime and heated to dissolve the copper electrolytic slime, and the copper electrolytic slime is dissolved. A method for smelting copper electrolytic slime, which is characterized by transferring substantially most of the base metal in electrolytic slime into slag, and producing high lead grade slag and high silver grade noble lead. (2) In the smelting method of copper electrolytic slime, which removes copper from the copper electrolytic slime or further roasts it to remove selenium after decoppering and dissolves it by adding flux and a reducing agent, silica 1 to 4 of the flux consisting of a lime flux and a lime flux, and the copper electrolytic slime.
% of the carbonaceous material and heated to dissolve the copper electrolytic slime, transferring a substantial majority of the base metal in the copper electrolytic slime into the slag, and adding a high lead grade to the slag. Slag and noble lead with high silver grade are generated, and then the slag is solidified and finely pulverized, gold, silver, selenium, and tellurium are concentrated and recovered as concentrate, the base metal is used as tailing, and the concentrate is A method for smelting copper electrolytic slime, which is characterized in that it is reprocessed in the copper electrolytic slime melting process described above. (3) The method according to claim (1) or (2), wherein the siliceous flux is silica sand or silica stone. (4) The method according to claim (1) or (2), wherein the lime flux is limestone or quicklime. (5) The method according to claim (1) or (2), wherein the base metal is at least one of lead, antimony, and bismuth. (6) The method according to claim (1) or (2), wherein the carbonaceous material is coke or coal.