DEVELOPMENT OF METHOD FOR REMOVAL THE NITRIC OXIDES FROM PROCESS OF PRECIOUS METALS RECOVERY FROM ANODE SLIME
Nitric compounds, especially nitric oxides, are extremely toxic with many unfavorable local effects, especially in the surrounding of great pollution sources. This work contains the results of laboratory research for involving of the best absorption parameters (temperature, type and concentration of absorption liquid), as well as a selection of absorption system for completely removal the nitric oxides from process of hydrometallurgical recovery of precious metals from anode slime in Plant for Anode Slime Treatment. The basic aim is decreasing of nitric oxides emission to the law approved concentration, both in working conditions and at gas emission point of the plant.
NOx suppression with hydrogen peroxide in the metals industry
Metal dissolution processes involving nitric acid are major sources of NOx. Technologies using hydrogen peroxide have been developed and proven on an industrial scale to suppress the emission of NOx from these processes. No changes are made to the dissolution process. Case histories are presented to illustrate the effectiveness of hydrogen peroxide with particular reference to the pickling of stainless steels.
A New Vacuum Pressure Infiltration CFRP Method and Preparation Experimental Study of Composite
In order to prepare a carbon-fiber-reinforced polymer composite (CFRP) with ideal microstructure and properties, a new vacuum pressure infiltration CFRP method is proposed based on an analysis of existing CFRP preparation process methods. Research on composite material preparation systems was carried out by using this new method principle. The system mainly includes a fiber pre-forming module, a vacuum heating infiltration module, a hot-press curing molding module, and a data acquisition control module. Under the conditions of natural curing at 0 MPa + 6 h + 25 °C, vacuum heating curing at –0.05 MPa + 30 min + 80 °C, and hot-press curing at 0.7 MPa + 5 min + 50 °C, a two-dimensional (2D) CFRP with excellent microstructure and properties was successfully prepared. Observing the microstructure of the prepared composite material, it can be found that the inside of the composite material was sufficiently and uniformly infiltrated, and common preparation defects such as holes and delamination were effectively controlled. Through the performance test, the bending strength of the material reached 790 MPa.