JPS62842B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for treating tellurium-containing materials obtained during lead/zinc smelting.

In general, tellurium is naturally found in acicular tellurite (Au, Ag) Te ₂ , tellurite pallidite (Bi ₂ .Te ₃ ), weissite (Cu ₃ .Te ₃ ), aludite (Pb.Te), and tetra Dymite (Bi ₂ .S.Te ₂ ), hethite (Ag ₂ Te), and kaleite [Cu
(Te,S)O ₄ .2H ₂ O] lead and zinc ore. Present in copper.

Therefore, when these lead, zinc, and copper ores are smelted, the tellurium contained in trace amounts in the ores becomes Pb,
When extracting metals such as Zn and Cu, they are concentrated into final metals and residues.

A typical example is when copper or lead is electrolytically refined, it is concentrated and collected in slime together with precious metals such as gold, silver, and platinum. In order to process this slime and obtain the tellurium it contains, it is necessary to separate the precious metals.

However, the above-mentioned separation process is complicated, requires careful attention, and has the disadvantage that the process is complicated. On the other hand, zinc smelting involves oxidizing zinc ore and/or lead ore in a roasting furnace and/or sintering machine.
Zinc pyro-smelting method (horizontal distillation method, vertical distillation method, electrothermal distillation method, blast furnace method) in which the obtained burned ore and/or sintered ore is mixed with a carbon-containing material such as coke and reductively distilled; There is a wet method in which metal zinc is obtained by leaching and extracting the ore and electrolyzing the extract.

Normally, in pyrometallurgical zinc smelting, molten zinc is obtained by condensing the zinc vapor generated by reduction, but this method is called “nonferrous metal smelting” (Japan Institute of Metals, Inc.,
Zinc vapor can be dissolved and recovered in molten zinc using a vacuum condenser as shown on page 98 of ``Published on February 20, 1964'', or a zinc splash condenser as shown in ``Special Publication No. 15587'', or 52-26213, the molten zinc is dissolved and recovered in molten lead, and then cooled and the molten zinc is separated and recovered by taking advantage of the fact that the solubility of zinc in lead decreases at low temperatures. method is being used.

The present invention is directed to the pyrometallurgical smelting of lead and zinc, particularly the smelting method using a splash condenser.
By shortening the process to remove tellurium, which is present in trace amounts in the raw ore,
The purpose is to increase the concentration and advantageously recover tellurium-containing substances.

In the present invention, a mixture of a tellurium-containing material and a _zinc -containing material is heated to
The first step is to obtain a mixed vapor of tellurium vapor and zinc vapor by heating to a temperature above ℃.The mixed vapor obtained in the first step is led to a condenser and cooled to below 600°C to form a molten mixture that absorbs tellurium. A treatment for a tellurium-containing material, comprising a second step of obtaining zinc, and a third step of concentrating tellurium in the dross obtained by washing the molten zinc obtained in the second step with chloride. It is the law.

The present inventors were researching a method for distilling zinc.
When tellurium was allowed to coexist in the raw material zinc, it was found that tellurium behaved almost in the same way as zinc. Furthermore, it has been found that when a melt of a binary zinc-tellurium alloy is washed with ammonium chloride, tellurium is concentrated in the generated dross.

This invention has been made based on the above findings.

In the present invention, tellurium-containing materials include lead ores containing tellurium minerals, tellurium pallidite (Bi ₂ Te ₃ ), tetradymite (Bi ₂ STe ₂ ), zinc ores, copper ores, gold and silver ores, and other metal ores. Further, intermediate products obtained by processing the slime and containing tellurium may also be mentioned. All of these tellurium-containing materials can be treated by the method of the present invention.

In addition, the zinc-containing material in the method of the present invention refers to a material containing metallic zinc or a zinc compound, and includes zinc ore containing zinc, sintered ore, intermediate products in zinc smelting, and zinc oxide obtained by residue treatment. etc.

In the first step of the present invention, tellurium is more easily reduced than zinc, and in the pyrometallurgy of zinc as in the present invention, lead is particularly reduced at the same time as zinc. If recovery is intended, the atmosphere in which the zinc is reduced, i.e.
Tellurium is sufficiently reduced and volatilized if the CO/CO ₂ ratio is 2 or more and the reducing atmosphere is 1000° C. or higher or equivalent.

By doing so, a mixed vapor of tellurium vapor and zinc vapor is generated. The weight ratio of tellurium and zinc in the mixture is not particularly limited.

Suitable equipment for carrying out this first step include a retort furnace (horizontal distillation furnace), a vertical distillation furnace, an electric distillation furnace, and a simultaneous smelting of lead and zinc, which are known in the above-mentioned distillation and smelting of lead. Examples include lead and zinc blast furnaces.

In the second step of the present invention, the tellurium and zinc mixed vapor generated in the first step is guided into a condenser in the same reducing atmosphere as in the first step to rapidly cool the tellurium vapor and convert it into molten zinc containing tellurium. It is important to obtain.

To cool the mixed vapor, a zinc condenser can be cooled externally to below 600°C. Also,
If a lead splash condenser is used, the vapor in the condenser may be cooled by a shower of molten lead to absorb tellurium and zinc into the molten lead.

In the third step of the present invention, the molten zinc that has absorbed tellurium and the molten lead that has absorbed tellurium and zinc obtained in the second step are washed with a chloride such as ammonium chloride or zinc chloride. . For cleaning, molten zinc that has absorbed tellurium, or molten lead that has absorbed tellurium and zinc, is continuously or intermittently fed into a suitable furnace or pot.
Add chloride continuously or intermittently. At this time, the atmosphere can be sufficiently separated in air. A better effect can be obtained by stirring at this time. The amount of chloride added may be selected from several ppm to several percent depending on the type of cleaning. If the resulting dross is left in the furnace or pot and only the molten metal is replaced continuously or intermittently, the amount of chloride added can be small. The treatment temperature may be 500°C or lower and is selected to be higher than the melting point of zinc. Particularly when stirring is performed, the reaction is extremely fast and completes within several minutes to several tens of minutes.

The reason why a mixed vapor of tellurium vapor and zinc vapor is obtained in the first step of the present invention is that metallic tellurium and metallic zinc are generally similar in melting point, boiling point, and other physical or chemical properties. This seems to be because there are.

The reason why molten zinc absorbing tellurium is obtained in the second step is thought to be due to the reasons described in the first step and the fact that tellurium and zinc become completely molten at high temperatures, depending on their weight ratios.

Furthermore, the reason why tellurium is concentrated in the dross obtained by washing with chloride in the third step is that when the molten zinc absorbing tellurium is cooled, ZnTe precipitates and migrates into the dross. , zinc oxide precipitates at the same time and transforms into dross. Furthermore, when molten lead is used in the second step, lead oxide is simultaneously precipitated and converted to dross. As a result, the tellurium quality in the dross is low.

In order to prevent this and obtain dross with a high tellurium grade, chloride is used to prevent the oxidation of zinc and lead and the transfer of these oxides to dross. In the present invention, only the oxidation of zinc and lead is suppressed by the chloride, without preventing the precipitation of ZnTe and the transition to dross.

The present invention is a method for treating tellurium-containing materials, which consists of the first, second, and third steps as described above. This is an easy method.

In addition, the final tellurium-concentrated dross can be recovered using conventional tellurium recovery methods such as caustic soda or sodium sulfide, such as acid leaching followed by electrolysis of the leachate, or alkaline leaching followed by adding a reducing agent. Tellurium can be recovered by known methods.

Note that if the second and third steps are carried out using a selenium-containing material instead of the tellurium-containing material in the first step, selenium will be concentrated in the dross obtained in the third step. An example will be described below.

[Example] Sintered ore (Zn: 43%, Pb: 22%, S: 0.5%, Te :0.02
%) in a lead-zinc melting furnace to evaporate lead and zinc, and at the same time evaporate tellurium.

These vapors were cooled by condensing zinc in a lead condenser.

The quality of the molten zinc in the obtained capacitor is
It was as follows.

Zn98.7%, Pb1.20%, Te50ppm The molten zinc thus obtained was washed by adding ammonium chloride, and the following results were obtained.

Processing conditions Ammonium chloride addition amount: relative to molten zinc
50ppm Processing temperature: 430 to 480℃ Processing time: 5 minutes Processing result Te grade in zinc after washing: 5ppm Te grade in dross: 10% Te recovery rate: 90% The dross obtained in this way After acid leaching, Te was obtained by electrolysis.

According to the method for treating tellurium-containing materials of the present invention, a suitable raw material for recovering tellurium can be treated with good yield through simple operations and without any complicated steps.

Claims (1)

[Claims] 1 A mixture of tellurium-containing materials and zinc-containing materials is
The first step is to obtain a mixed vapor of tellurium vapor and zinc vapor by heating to a temperature of 1000°C or higher in a reducing atmosphere with a CO ₂ ratio of 2 or more, and the mixed vapor obtained in the first step is guided to a condenser. A second step of cooling to below 600°C to obtain molten zinc that has absorbed tellurium, and a third step of concentrating tellurium in the dross obtained by washing the molten zinc obtained in the second step with chloride. A method for treating tellurium-containing materials, characterized by comprising the steps of: