Waste Water from the Production of Titanium Products as a Raw Material for the Ti(OH)4, NaOH and HCl Production

The study of the spent acidic pickling solution (SAPS) processing is presented. The solution is formed in the process of etching titanium products with hydrochloric acid. The processing includes the stages of neutralizing the SAPS with alkali, filtration and drying of the titanium hydroxide precipitate, electrochemical processing of the filtrate containing sodium chloride in an electrolyzer with ion-exchange membranes. The electrolysis process produces sodium hydroxide and hydrochloric acid. The proposed scheme for processing the SAPS makes it possible to obtain titanium hydroxide, sodium hydroxide and hydrochloric acid. Titanium hydroxide can be used in various industries. Alkali can be used in the SAPS neutralization process. Hydrochloric acid after the adjustment is suitable for use in the etching of titanium products.

Hydrothermal synthesis of tetragonal barium titanate nanopowders under moderate conditions

Monodispersed tetragonal barium titanate (BaTiO3) nanopowders were synthesized by a convenient hydrothermal route at a low temperature of 200?C in only 24 h. The key point of this method is to promote the generation of ultrafine titanium hydroxide precipitation precursors with the help of absolute ethyl alcohol and ammonia solution during the hydrolysis of Ti(OC4H9)4. The results of X-ray diffraction and Raman spectra show that the as-prepared BaTiO3 nanopowders possess tetragonal-dominant structure. The synthesized tetragonal BaTiO3 nanopowders exhibit relatively uniform size and good dispersity, with the average particle size of 96.1 nm and a tetragonality of 1.0073, which enable broad application prospects in the field of multilayer ceramic capacitors.

Titanium hydroxide as precursor for obtaining functional materials

It was found that finely ground powders can polymorphically transform into other nonequilibrium crystalline phases in the study of phase transformations of X-ray amorphous titanium hydroxide (TH) in the process of mechanical activation in the presence of additives in the form of zinc compounds. Judging by the increase in the intensity of the peaks in the diffraction patterns, it can be stated that amorphous phase crystallizes in the form of anatase and brookite as a result of high-energy exposure. It is shown that the lower the degree of hydration of titanium hydroxide, the efficiency of the mechanical effect of the additive on phase transformations is higher. The following trend for the effect of the introduced modifier is observed — ZnSO4·7 H2O > > Zn(NO3)2·6 H2O > ZnO. This dependence is due to the combination of physical and chemical transformations of the material located in the field of intense mechanical influence, confirmed by data on the calculation of crystallite size and microstrains. The conversion of excess mechanical energy into thermal energy initiates chemical processes with the formation of solid titanium-zinc solutions, which accelerate the restructuring of the crystalline structure upon calcination of the modified titanium hydroxide according to the scheme: anatase-brookite-rutile. The obtained results have the prospects of practical application in the production of the so-called “rutile” nuclei used in the industrial production of titanium dioxide for various purposes.

EVALUATION OF EFFECTIVENESS OF USE OF COMPLEX COAGULANTS FOR WASTEWATER TREATMENT PROCESSES OF MECHANICAL ENGINEERING

In the course of the work, the quantitative and qualitative characteristics of the wastewater of the machine-building enterprises of the Moscow and Penza regions were investigated. It was found that in most cases the most difficult to remove contaminants are oil products entering the wastewater from metal processing operations, as well as heavy metal ions. Due to the lack of separation of stormwater, industrial and domestic sewage systems, the effluent under study had high concentrations of dissolved organic compounds (Biological Oxygen Demand BOD/chemical oxygen demand COD) and suspended solids. Laboratory tests of experimental samples of complex coagulant on waste water of real production were carried out. Normal aluminum sulfate and aluminum sulfate modified with hydrolysis products of titanium tetrachloride (complex coagulant) were used as reagents. It has been established that complex titanium-containing reagents are effective in the processes of coagulation sewage treatment of machine-building enterprises. The process of flocculation and sedimentation proceeded at a high rate due to flocculation reactions on the surface of titanium hydroxo-complexes, as well as nucleation phenomena on the surface of titanium hydroxide particles. The increased efficiency of samples modified by hydrolysis products of titanium coagulant compounds with respect to traditional aluminum sulfate has been proved. The consumption of complex coagulant compared with aluminum sulfate was about 1.25 - 1.5 times lower, while its efficiency is about 5 - 10% higher. The increased efficiency of complex coagulants with respect to the indicators of oil products, COD and color (organic pollutants) was noted, which is due to the developed adsorption surface of titanium hydroxide flakes in comparison with aluminum hydroxide.