Estimation of quality of hot pressed briquettes as a type of metallurgical charge materials

The basic principles of construction are formulated in the work and a description of the technological process of hot briquetting of ferrous metal waste as a way of converting fine metal particles into a dimensional semi-finished product of a given size and chemical composition is given. The description of equipment for the implementation of this process with highly efficient non-oxidizing heating and complete safe neutralization of flue gases is given. The results of melting of hot-pressed briquettes in various melting units are presented. It is shown that briquettes cleaned from coolant with a density of 6500–7100 kg/m3 are full-fledged substitutes for bulk scrap. Recommendations and a feasibility study on the feasibility of introducing the hot briquetting process into production at the enterprises of the bearing, machine-building and metallurgical industries, followed by the use of hotpressed briquettes to produce cast billets for their own purposes, are given.

RESEARCH OF POSSIBILITY OF USING CHEMICAL METHOD OF FINE METAL PARTICLES REDUCTION FOR BACTERICIDAL SORBENTS PRODUCTION

The present paper is concerned with a research of sorption and bactericidal properties of the fine metal particles applied on the surface of active carbon fabric by chemical sedimentation method. The ascorbic acid and natrium borane were used in the study process as metals, copper and silver reducing agents. Influence of reducer and fine metal nature onto the porous structure, as well as bactericidal and sorption characteristics of obtained fibrous sorbent samples are shown. It is determined that use of ascorbic acid for synthesis of copper and silver fine particles on the active carbon fabrics surface leads to the considerable decrease in a specific surface and volumes of meso - and micropores of the obtained sorbent in comparison with initial active carbon fabric. When using the natrium borane as reducer of fine copper particles the decrease in a specific surface and volumes of sorption pores is also observed. However, when using the natrium borane, the active carbon fabric samples modified with silver particles or with their composition with fine copper particles, had the higher values of porous structure main characteristics in comparison with the initial active carbon fabric. The nature of distribution of fine metal particles at the active carbon fabric surface was investigated by the electronic microscopy method. It was found that during the chemical reduction process the particles of fine copper attached to active carbon fabric fibers, being almost evenly distributed at all surface of fabric. Particles of silver were located as crystal congestions along fibers. Sorption and bactericidal properties of the received samples of modified active carbon fabrics are investigated. Their high sensitivity to microorganism cells which remains during a long storage period is demonstrated. Herewith, the active carbon fabric, modified with particles of fine copper and silver, keeps high sorption properties.

Catalysis with Room Temperature Ionic Liquids Mediated Metal Nanoparticles

There has been still a growing interest in ionic liquids (ILs) for catalysis, in particular considering their tremendous success made over the past decades. Indeed, ILs for catalysis has been a main subject in chemistry and technology, and a rough estimate is that more than 6000 publications involving IL catalysis have been reported in the past fifteen years. Since there have been a large number of excellent reviews and books concerning the catalysis in ILs, in this chapter the authors mainly focus on the IL immobilized nano- or super-fine metal particles for catalysis, which could bridge or fill the gap between homogeneous and heterogeneous catalysis. Detailed IL-immobilized catalyst preparation, characterization and their application in hydrogenation, C-C coupling, oxidation, etc. will be discussed.