The sulfuric acid method (пишите любо текс, либо рисуйте схему)

The method is based on the reaction between sulfuric acid and ß-spodumene (there is virtually no interaction between ɤ-spodumene and sulfuric acid) in which the hydrogen of the acid is substituted for the lithium without a change in the structure of the mineral:

After the enrichment (by decrepitation) the cooled and crushed (in a roller mill, to a particle size of -0.074") material is fed to a horizontal screw-conveyer or rollers in which it is mixed with concentrated (9370) sulfuric acid by a sprinkling technique.

The sinter formed is cooled and leached with water to extract the Li₂S0₄. The solution is separated by filtration on a drum-type vacuum filter and the magnesium and calcium are removed from the solution by precipitation, respectively, as magnesium hydroxide and calcium carbonate. The iron and aluminum are precipitated as the hydroxides by adding sulfuric acid to the solution (to pH 7) together with a small amount of carbon black,

The solution is filtered and lithium carbonate is precipitated by the addition of a saturated solution of sodium carbonate. The lithium carbonate is washed twice with deionized water yielding a product with a carbonate content of 96 to 97%. The precipitate is separated by centrifuging, and dried at a reduced pressure .The dry lithium carbonate is contaminated with sulfate ions, chloride ions, the oxides of sodium, potassium, iron, calcium, and the heavy metals, and contains 0.01 % moisture.

28. Create a modern technological scheme of processing of mineral raw materials containing beryllium.

The average concentration of beryllium in the Earth's crust is 6*10^-4. There are more than 30 known beryllium minerals; the most common are beryl, chrysoberyl, phenacite, helvite, danalite, and bertrandite. Beryl is the main commercial beryllium mineral, but phenacite and helvite are also of commercial value. The main beryllium ore deposits are found in Brazil, Argentina, Congo (Leopoldville), India, Southern Rhodesia,  Australia,and the USA (South Dakota and California). All these deposits contain mostly beryl. The largest phenacite and helvite deposits are in Norway.

Two industrial methods for the decomposition of beryl are used at present: the fluoride method and the sulfate method.  Sulfate process, H₂SO₄

1. Alkaline treatment

Be₃Al₂(Si₆O₁₈) + 7CaO = 3CaBeSiO₄ + CaO·Al₂O₃ + 3CaSiO₃; CaBeSiO₄ = BeO + CaSiO₃

2. Heat treatmentBeryl is melted (1650 °C) and quenched in water. After treatment 50-60 % beryl has a greater solubility in H₂SO₄ heat treatment renders of 90-95 % of the beryl soluble.

3. Leaching with water

4. Filtration SiO₂

5. Separation, alum separation, chelate separation, (NH₄)₂CO₃ separation

6. Hydrolysis

7. Drying Be(OH)₂

BeSO₄ + 4 NaOH = Na₂BeO₂ + Na₂SO₄ + 2H₂O

Na₂BeO₂ + 2H₂O = Be(OH)₂ + 2NaOH

29. Critically evaluate complex processing of technologic industrial products and wastes of rare metal production

Proceeding from the situation in the field of enrichment, the priority scientific and technological directions are:

- creation of the new technologies and devices providing enrichment of particles of the microdisperse sizes and complex mineral raw materials;

- enhancement of technologies of enrichment of ores of non-ferrous, rare and precious metals due to creation of new flotoreagent and sorbents from anthropogenous raw materials;

- carrying out a tekhnologo-mineralogical kadastrization of fields of bark of aeration, waste of the entities of MMC for assessment of a possibility of their economic conversion and identification of the perspective directions of scientific and technological researches;

- the organization based on the field of Borla of deep primary conversion of ores of non-ferrous metals, creations of new technologies of their high-complex enrichment.

Implementation of the listed actions will allow to raise sharply indicators of conversion of ores of Kazakhstan at an enrichment stage, and also to raise end-to-end indicators on extraction and complexity on the scale of all mining and processing metallurgical complex of Kazakhstan. Their successful implementation is equivalent to start in operation of several new fields.

In the country cumulatively more than 20 billion tons of the technogenic waste of mining and metallurgical complex belonging to the state according to the presidential decree of the republic.

They need to be considered as an independent source of raw materials of metallurgy of Kazakhstan. Now no more than 2% of all cumulative solid waste are processed, that is the related environmental problems aren't solved.

The main priority in recycling of the collected technogenic raw materials are:

- development of the new technologies of conversion of technogenic secondary raw materials allowing to take valuable components in a commodity product. The important direction of innovative development of an industry is creation of new technologies and productions;

- carrying out researches, development of new technologies for complex conversion of mineral raw materials of fields of tin, nickel, tungsten, molybdenum and production organization of these metals;

- carrying out researches, development of priority technologies for receipt of powder metals and handling of the non-ferrous metals allowing to develop own machine-building industry;

- development of new technologies of receipt of lead-calcium, lead-nickel and other types of alloys for development of automotive industry, production of rare-earth products and development of its source of raw materials;

- a stainless steel manufacture and obtaining from it high-quality rolled metal.

In recent years production and export of ferrous and non-ferrous metal grow on amount and the nomenclature, however internal consumption of these metals in the republic increases extremely poorly, 93-97% of the made non-ferrous metal go abroad.

High-technology products (products with a high value added) from domestic metal in Kazakhstan are practically not made and not exported.

Results of SWOT analysis of metallurgical industry are below included:

Strengths:

- availability of own material source of raw materials;

- the developed infrastructure;

- production and technological experience;

- wide range of metals;

- highly professional personnel case.

Weaknesses:

- aging of business assets;

- lack in technology;

- complex composition of ores;

- low level of repartition and small nomenclature of hardware;

- insufficient inflow of a young personnel.