Method for processing molybdenum concentrates and middlings

 

(57) Abstract:

The invention relates to metallurgical industry, namely the processing of molybdenum concentrates and middlings. The method includes oxidizing roasting at a temperature of 550-600oWith that lead in two stages: the first stage is performed with the lack of oxygen to the degree of desulphurization cinder 85-95%, the second stage leads to complete oxidation of the sulphur and the formation of metal oxides with excess oxygen in 1,5-2,0 times the stoichiometry. Simultaneously distilled volatile oxides of rare metals and then catch them by means of absorption. The method improves the extraction of rhenium and other rare metals in the gas phase up to 93-95%, increase the recovery of rhenium and other rare metals to 2.4 and 3.3 g/l in the absorption solution, reduces the sulfur content in the calcine to 0.5%; easy to follow; provides environmentally friendly process for reducing the concentration of sulfuric acid in solution. table 1.

The invention relates to the field of non-ferrous metallurgy, in particular to the processing of molybdenum concentrates and middlings, and can be used in the metallurgical industry for production of ferromolybdenum and extraction of rhenium and other oxidative roasting with simultaneous distillation of the volatile oxides of rare metals and their subsequent capture by absorption, moreover, oxidative roasting of lead into the cyclone at a temperature of 1350-1600oWith a coefficient of excess oxygen 1.2 to 1.5 with respect to stoichiometry [see p. Germany 3843172, publ. 5.07.90,, MKI C 01 G 39/02].

The disadvantages of this method are that in the specified range of temperatures in the gas phase passes 50-90% of molybdenum trioxide, although the oxidation of sulfur dioxide to trioxide does not occur. In addition, this method is impractical for processing raw materials containing rhenium and other rare metals, due to dilution of small amounts of trapped oxides of these metals molybdenum trioxide, leading to their loss.

Also known is a method of processing molybdenum concentrate, including oxidative roasting with simultaneous distillation registergui gases at a temperature of 550-590oC. the Calcination is carried out in a multiple-hearth furnaces [see A. N. Zelikman, "Molybdenum", M.: metallurgy, 1970., S. 37-39].

The disadvantages of this method are

- limited extraction of rhenium (sublimation rhenium under oxidative roasting in multiple-hearth furnaces not more than 70%);

- dust (up to 18%);

technological difficulties (it is difficult to maintain the optimum firing temperature for each deck).

However, the known method does not provide a high degree of sublimation of rhenium (not more than 50%), the content of total sulfur in the calcine is about 1%.

The closest in technical essence and the achieved result of the claimed invention is a method for processing molybdenum concentrates and middlings, including oxidative calcination at a temperature of 550-600oWith simultaneous distillation of the oxides of rare metals and their subsequent capture by absorption. Firing lead with a coefficient of excess oxygen from 1.8 to 2.2 in relation to the stoichiometry in the furnace of the fluidized bed. The sulfuric acid concentration in the absorption solution 100 g/l, rhenium - 0.1-0.5 g/l [A. N. Zelikman, B., kites "metallurgy of rare metals", M.: metallurgy, 1991, S. 46-47].

The disadvantages of the prototype method:

- high content of sulfur in the calcine (sulfate sulfur% to 2%, sulfide - 0.5%), preventing its further use in the production of ferromolybdenum;

significant pylones (40%);

- loss of rhenium and other rare metals (more than 50%) due to inefficient interaction with absorption solutions
technological difficulties and the complexity of the hardware design process.

The present invention is to increase the efficiency of the method due to the technical result - the increase of degrees of separation and absorption in the absorption solutions of volatile oxides of rare metals, in particular oxide of rhenium Re2O7and reducing the content of sulfur in the calcine.

The technical result is achieved in that in the method for processing molybdenum concentrates and middlings, including oxidative calcination at a temperature of 550-600oWith simultaneous distillation of volatile oxides of rare metals and their subsequent capture by absorption, according to the invention the oxidative roasting of lead in two stages, the first stage is performed with the lack of oxygen to the degree of desulphurization cinder 85-95%, and the second lead to complete oxidation of the sulphur and the formation of metal oxides with excess oxygen in 1,5-2,0 times the stoichiometry.

The claimed conditions of the method are necessary and sufficient for its effectiveness due to the fact that:

- the lack of oxygen in the first stage of oxidative roasting provides a high degree deal is B>O7and others);

- the basic amount of sulfur dioxide formed in the first stage, derived from the burning zone and subsequently excluded from the process of mass transfer in the gas - liquid transition of gaseous oxides of rare metals in the absorption solution, reducing the production of sulfuric acid;

the excess oxygen in the second stage oxidizing roasting promotes complete complete oxidation of the residual amount of sulfur and the formation of volatile molybdenum trioxide (Moo3) and oxides of rare metals, rhenium, osmium, and others).

Analysis of the known technical solutions allows to make a conclusion that the claimed invention is not known from the prior investigational technique that demonstrates its compliance with the criterion of "novelty".

The essence of the claimed invention to a person skilled not obvious from the prior art, which allows to make a conclusion about its compliance with the criterion of "inventive step".

The possibility of processing of molybdenum concentrates and middlings in the present conditions in the domestic metallurgical enterprises demonstrates compliance invention, the criterion of "industrial applicability".

Example 1. Processing of molybdenum concentrates.

For processing used granules (2-4 mm) molybdenum concentrate humidity of about 5% content, %: Mo 32,000; S 26,000; Re 0,076.

Processing was carried out in a tubular rotary kiln with external electrical heating capacity 15 kg/h of Oxidation firing is conducted in two stages. In the first stage molybdenum concentrate was annealed at a temperature of 550oWith the lack of oxygen to the degree of desulphurization cinder 85%. Gases were discharged. In the second stage oxidation firing is conducted at a temperature of 550oAnd oxygen excess relative to the stoichiometry of 1.5 times. At the second stage firing occurred distillation of volatile oxides of rare metals, which are then caught by the absorption solution circulating to developments in sulfuric acid, 320 g/L. the Concentration of rhenium in the absorption solution was 2.4 g/L. the Content of total sulfur in the calcine of 0.5%.

In the conditions of example 1 was carried out by the processing of molybdenum concentrates in examples 2-3 with varying ratios in the inventive within analogichnye shown in these examples. In addition, a processing of molybdenum concentrates in the conditions of the prototype method [A. N. Zelikman, B., kites "metallurgy of rare metals", M. : metallurgy, 1991, S. 46-47] - see example 4.

Conditions of implementation of the method and the results of the analysis of the obtained products are shown in the table.

As seen from the above examples and table data, using the proposed method of processing molybdenum concentrates and middlings in comparison with the known method, taken as a prototype [A. N. Zelikman, B., kites "metallurgy of rare metals", M.: metallurgy, 1991, S. 46-47], provides the following technical and community benefits:

- improving the extraction of rhenium and other rare metals in the gas phase up to 93-95%;

- improving the extraction of rhenium and other rare metals to 2.4 and 3.3 g/l in the absorption solution;

- reduction of the sulphur content in the calcine to 0.5%;

- easy implementation of the method;

- environmentally friendly process for reducing the concentration of sulfuric acid in solution.

Method for processing molybdenum concentrates and middlings, including oxidative calcination at a temperature of 550-600oWith simultaneous distillation of Letuchiy lead in two stages, the first stage is performed with the lack of oxygen to the degree of desulphurization cinder 85-95%, and the second stage leads to complete oxidation of the sulphur and the formation of metal oxides with excess oxygen in 1,5-2,0 times the stoichiometry.

 

Same patents:

The invention relates to the field of non-ferrous metallurgy, in particular to a method of processing lead waste containing precious and rare metals
The invention relates to hydrometallurgy and can be used for membrane extraction, concentration and purification of metals both in technology and analytical practice
The invention relates to hydrometallurgy rare metals and can be used for desorption of rhenium

The invention relates to waste latinoreview catalysts on AL2ABOUT3basis

The invention relates to the field of non-ferrous metallurgy

The invention relates to methods for extracting rare metals and can be used for separation of rhenium and other rare and precious metals from gas emissions from active volcanoes, fumaroles gases, gas emanations lava flows, lava lakes
The invention relates to a method for producing fine powder (3 - 5m) alloy of rhenium and molybdenum in the ratio 1 : 1

The invention relates to a method for production of metallic technetium from industrial concentrates pertechnitat potassium, including the dissolution of hanging pertechnitat potassium in water, ion exchange cleaning solution on the cation exchanger in the hydrogen form with obtaining a filtrate-technecally acid neutralization technecally acid ammonia solution, evaporation of the solution, deposition pertechnitat ammonium and restore it to the metal

The invention relates to a process for recovering rhenium and molybdenum liquid extraction of secondary amines from sulfuric acid solutions followed by ammonia reextracting

The invention relates to a process for recovering rhenium from nitrate-sulfate solutions, mainly from hydrometallurgical solutions redistribution molybdenum concentrates, including sorption of rhenium on the weakly basic anion exchange resin containing as functional groups, secondary amino group, the regeneration of the anion exchange resin desorption rhenium solution of an alkaline reagent and reuse of anion exchange resin to extract rhenium

The invention relates to the field of hydrometallurgy of non-ferrous and rare metals and can be used for the extraction of molybdenum (IV), presents an anionic form in solution

The invention relates to the extraction of substances extraction and can be used in ferrous and nonferrous metallurgy, as well as treatment of industrial and domestic wastewater

The invention relates to the production of highly pure compounds molybdenum and bismuth from various types of raw materials

The invention relates to the processing of molybdenum concentrate

The invention relates to a process of producing compounds of molybdenum: molybdenum disulfide having anti-friction properties, obtained by heat treatment of the mixture trisulde molybdenum and sodium sulfosalicylate

The invention relates to ferrous metallurgy, in particular the production of molybdenum trioxide

The invention relates to metallurgy, and more specifically to the production of ferroalloys, in particular the production of ferromolybdenum
The invention relates to the metallurgy of rare metals and can be used in firing technology molybdenum concentrates and middlings

The invention relates to the preparation of iron ore concentrates for metallurgical treatment by improving their quality due to the removal of undesirable impurities contained in concentrates, primarily phosphorus
Up!