PROCESSING OF WASTES HIGH-TEMPERATURE HEAT-PROTECTIVE MATERIAL

The assessment of waste generated during the production of high-temperature fiber insulation. A method of waste processing with a minimum number of technological stages is presented. The structure and mechanical characteristics of the obtained material are estimated. Full-scale tests of the material under the influence of high-enthalpy flame flow of propane-oxygen burner were carried out. The resulting material is suitable for the production of furnace linings, heat-resistant substrates and containers, flame screens.

Extraction Factor Of Pure Ammonium Paratungstate From Tungsten Scraps

Typical oxidation process of tungsten scraps was modified by the rotary kiln with oxygen burner to increase the oxidation rate of tungsten scraps. Also to accelerate the solubility of solid oxidized products, the hydrothermal reflux method was adapted. By heating tungsten scraps in rotary kiln with oxygen burner at around 900° for 2hrs, the scraps was oxidized completely. Then oxidized products (WO3 and CoWO4) was fully dissolved in the solution of NaOH by hydrothermal reflux method at 150° for 2hrs. The dissolution rate of oxidized products was increased with increasing the reaction temperature and concentration of NaOH. And then CaWO4 and H2WO4 could be generated from the aqueous sodium tungstate solution. Ammonium paratungstate (APT) also could be produced from tungstic acid using by aqueous ammonium solution. The morphologies (cubic and plate types) of APT was controlled by the stirring process of purified solution of ammonium paratungstate.

Numerical Simulation of Different Coal Combustion in Two Tiny-Oil Ignition Burners With Oxygen-Enriched

Two tiny-oil ignition combustion burners with oxygen-enriched were studied in this paper. One is adding oxygen directly into primary air, and the other is adding oxygen by extra adding-oxygen tube. The bituminous coal, the lignite, and the meager coal, are simulated in these burners. By comparing the two different combustion characteristics, the simulation results show that, for bituminous coal, the high temperature zone congregates in the first directly added oxygen burner, while, for the meager coal, it is difficult to burn in the first directly added oxygen burner. As to the lignite, because of its characteristics of high volatility and low heating value, the first directly added oxygen burner provide oxygen timely for its high volatile, its flame combust more quickly and directly.

Effect of Alumina Starting Materials on Spheroidization in Flame Fusion Method

Alumina powder is used to improve the heat conduction and physical properties of heat radiation sheets, these properties can be improved by increasing the filling rate of alumina. Spherical alumina powder is being actively developed to improve the filling rate of alumina in sheets. In this study, a high-temperature flame was created by the flame-fusion method using an oxygen burner to produce spherical alumina. We investigated how the chemical composition and particle size of starting materials affect their fusion behavior under flaming conditions during spherical alumina production using the flame-fusion method. Boehmite and aluminum hydroxide, which accompany the endothermic reaction due to the dehydration of the starting materials, showed lower spheroidization ratios than sintered alumina. The spheroidization ratio improved as the particle size of the starting materials decreased.