ABSTRACT
dissertation for the degree magistr 6M070900 specialty – Metallurgy Yessenova Akerke Yessenkyzy
THE STUDY OF DEMINERALIZATION PROCESSES OF TITANIUM AND MAGNESIUM PRODUCTION INDUSTRIAL WASTES
Ust-Kamenogorsk Titanium and Magnesium Plant is the only producer of titanium sponge, titanium ingots and slabs in Kazakhstan.
Titaniumconcentratessubjectedtoorethermalmeltingandsubsequentchlorinationinme ltingofalkali-metalchloride (natrium, potassium, magnesium) with obtaining the titanium tetrachloride are used as raw material for titanium preparation. Further titanium tetrachloride is reduced by magnesium to obtain titanium sponge [1-4].
Magnesium is prepared from carnallite MgCl2·KCl·6H20 using the electrolytic method. The chlorine obtained in the electrolysis process is passed to the production of titanium. Raw magnesium is passed for refining and production of magnesium ingots, used to recover titanium tetrachloride [4,5]. Production of titanium ingots and alloys includes areas of weighing and blending, compacts pressing and electrodes assembling, plasma welding, VAR furnaces, crucibles cleaning, ingots machining.
The theme actuality. Titanium and magnesium are essential constructional metallic materials, its production is combined in two parallel and interconnected production lines.
The technology of titanium and magnesium production and processes of the solid waste removal and neutralization gas emissions are associated with the consumption of significant amounts of water. In the production of magnesium and its alloys about 4.5 meters of waste water per tonne of product are formed, in the production of titanium - 20.5 m / t of production.
Production waste water is formed as a result of absorption purification of gas emissions containing chlorine and its compositions and hydraulic washing-out of sludges of titanium raw materials chlorination units, characterized by high content of metal chlorides.
Traditionally, wastewater neutralization is produced by mixing streams, averaging and neutralizing by calcium-containing reagents, followed by flocculation of formed suspensions, sediment precipitation, its condensation or dehydration. The existing wastewater treatment technologies do not provide the requirements for the quality of treated water on the content of heavy metals ions, suspended solids, mineral impurities (chlorides of calcium, magnesium and sulphate), which does not allow them to drop into the open water without further processing or dilution.
For the decision of this problem, artificial hydraulic engineering constructions are commonly used - industrial channels in which the processes of mixing, dilution and further purification by changing the pH occurs. However, as a
rule, in this case, it is not possible to achieve the required quality of purifying and highly mineralized effluents get into surface waters.
A feature of the titanium-magnesium production wastewater is the content of metal ions of different nature (alkali, alkaline-earth, microcoulombmeter, including ions with amphoteric characters). The degree of neutralization and wastewater quality under reactant treatment will depend on pH subsidence, hydroxides solubility, and possibility of hydroxocomplexes formation etc., therefore optimizing of wastewater chemical treatment conditions allows to increase the efficiency of neutralization.
The high content of suspended substances in purified water is often determined by conducting of suspensions flocculation process in a non-optimal mode, and also use of ineffective methods of concentration and sludge drying, for example, gravitation with return formed when water concentrates on waste treatment facilities.
In conditions of strengthening of requirements to discharged wastewater quality with high salt content is relevant to methods development of its demineralization followed by a return to the production cycle.
Reduction of environmental load of titanium-magnesium production on hydrosphere facilities is a topical environmental and technological problem which requires a solution.
The goal of the work: the study of demineralization processes of titanium and magnesium production industrial wastes
To achieve the goal it was necessary to solve the following aim:
To conduct a complex ecological and technological analysis of formation conditions and technology of titanium-magnesium production wastewater disposal.
To explore wastewater demineralization process using rotary vacuum evaporator.
The research objects. Wastewater and waste water sewage of titanium- magnesium production by the example of UKTMP JSC Ust-Kamenogorsk.
Scientific novelty of the work. Under laboratory conditions, the expediency of the use of thermal methods for demineralization wastewater titanium and magnesium production. To this end, a method has been tested direct thermal desalination wastewater using a rotary vacuum evaporator, which reduces the amount of solid residues (up to 23-26 tons / day, humidity 50-60%) and contributes to the creation of more effective closed-loop water supply at JSC
"UKTMP ".
Established the possibility of using a concentrated solution formed by demineralization of the clarified wastewater as icemelter.
It was also analyzed with the use of the resulting residue demineralization for preparing solutions used in drilling oil wells.
The work approbation, publications. Materials of the work presented in 2 publications in the scientific conference, which was held in East Kazakhstan State Technical University. D.Serikbaev. XVI Republican scientific-technical conference of students, graduate students and young scientists "Creativity young -
the innovative development of Kazakhstan" April 14-15, 2016 in Ust- Kamenogorsk.
- Effective methods of demineralization wastewater titanium and magnesium production.
- Research of modern technological and ecological problems of industrial wastewater.
