FEATURES OF THE FORMATION OF THE COATING STRUCTURE ON TITANIUM-BASED ALLOYS

Previously shown that coatings formed on titanium by plasma electrolytic oxidation (PEO) in an electrolyte with zirconium sulfate Zr(SO4)2 consisted of ZrO2 and TiO2 oxides, their surface layer is enriched with zirconium, they have good protective properties in chlorine-containing media. The resulting layers have a fairly regular distribution of relatively small pores, with a diameter of about 1 μm or less, on the surface. The composition and structure of PEO layers depend on both the composition of the electrolyte and the modes of formation. It is of scientific and practical interest to elucidate the effect of the conditions for the formation of coatings with ZrO2 on titanium and its alloys on their anticorrosive properties in chlorine-containing media. Samples for research were formed under anodic (unipolar) conditions at the same current density and different formation times. The samples were formed in modes with current density 0.08 A/cm2 and processing time (minutes) − 8.5; 9.5; 10; 11; 12; 13; 14; 15; 20; 30; 40; 60. The duration of treatment was chosen as to maximally repeat the anticorrosive characteristics obtained in the previous case. The work uses modern research methods, including electron microscopy, presents the results of further study of ZrO2 + TiO2 / Ti systems formed in an electrolyte with zirconium sulfate Zr(SO4)2. It has been established that coatings are formed on titanium and its alloys in an electrolyte with zirconium sulfate under galvanostatic conditions of the PEO process at i = 0.08 A / cm2 during a processing time of 11-15 min. There is a correlation between the stages of galvanostatic formation of coatings and their anticorrosive properties.

Synthesis of Low TENORM Zirconium Sulfate from ZrO(OH)2 with Sulfuric Acid

Zirconium sulfate (ZS) has become one of the alternative chemical compounds for substituting traditional tannery substances using chromium(III) which was not environmentally friendly. The purpose of this research was to synthesize ZS from ZrO(OH)2 using H2SO4 with low Technologically Naturally Occurring Radioactive Material (TENORM) content. This ZS synthesis process shortened the old processing flow at which plenty of chemical reactors were used. The results showed that with 300 mg of feed, 600 mL of 95% H2SO4, at a temperature of 250 °C, the contact time of 150 min, the obtained conversion was 77.76%. Furthermore, in this 95% acid leaching reactor, the SiO2 content was still 2.79% and it was not TENORM free yet, but the FTIR and XRD images were in accordance with BDH standards. Moreover, the quenching process results had been free of SiO2 and TENORM content, but they still contained 1.48% HfO2. The surface of the TEM images from the quenching results had been in the form of elongated and transparent crystals. The result of the economic feasibility analysis showed that the new ZS synthesis process was more economical or profitable when it was compared to the old ZS synthesis process, with a BCR value of 1.258.

Basic Sulfate Precipitation of Zirconium from Sulfuric Acid Leach Solution

H2SO4 was ensured to be the best candidate for Zr leaching from the eudialyte. The resulting sulfuric leach solution consisted of Zr(IV), Nb(V), Hf(IV), Al(III), and Fe(III). It was found that ordinary metal hydroxide precipitation was not feasible for obtaining a relatively pure product due to the co-precipitation of Al(III) and Fe(III). In this reported study, a basic zirconium sulfate precipitation method was investigated to recover Zr from a sulfuric acid leach solution of a eudialyte residue after rare earth elements extraction. Nb precipitated preferentially by adjusting the pH of the solution to around 1.0. After partial removal of SO42− by adding 120 g of CaCl2 per 1L solution, a basic zirconium sulfate precipitate was obtained by adjusting the pH to ~1.6 and maintaining the solution at 75 °C for 60 min. Under the optimum conditions, the loss of Zr during the SO42− removal step was only 0.11%, and the yield in the basic zirconium sulfate precipitation step was 96.18%. The precipitate contained 33.77% Zr and 0.59% Hf with low concentrations of Fe and Al. It was found that a high-quality product of ZrO2 could be obtained from the basic sulfate precipitate.

Study on the Catalyst Performance on Cornus wisoniana Oil Catalytic Cracking Prepared Biological Fuel Oil

In our Research, we Used Cornus Wisoniana oil as Feedstock and the High Temperature Pyrolysis Kettle as the Reactor. Examine the Performance of Lanthanum Oxide, Zirconium Sulfate, Calcium Oxide and KF Loaded Catalyst on Cornus Wisoniana oil Catalytic Cracking Reaction. and through the SEM, XRD and FT-IR, Optimal Catalysts were Used to Characterize the Structure. the Results Showed that among KF Modified Catalyst KF Supported on Cao Produced Highest Yield of Bio-Fuel Oil from Cornus Wisoniana oil. when the Dosage of Catalyst Reached 1%, KF Impregnation Ratio of 40%, and Catalyst Calcination for 4h at 600°C, it can be Obtained Highest Yield of Bio-Fuel Oil about 82.7% and Reaction Rate up to 94.1. in Addition to the KF/MgO Having Low Yield about 60.6%, Catalytic Activity of other Four KF Catalysts were Higher than that of Lanthanum Oxide, Zirconium Sulfate and Calcium Oxide. the Catalytic Efficiency of Lanthanum Oxide and Zirconium Sulfate Appeared Similarity and are all Low. the Catalytic Activity of Calcium Oxide is Slightly Higher than the Lanthanum Oxide and Zirconium Sulfate, but Lower than that of KF/CaO Catalyst.