RECYCLING OF FERROUS METAL SHAVINGS

The most advanced and universal way of chips recycling of ferrous metals is the technology of direct chips remelting in rotational tilting furnaces (RBF) directly at the enterprises-sources of waste generation. However common practice of iron and steel chips recycling is based on its briquetting and subsequent remelting in traditional furnaces.For cost reduction when chip briquetting and organization of hot briquetting sections in places of its formation highly efficient equipment – rotational dryer and RBF is proposed. The possibility and effectiveness of developed furnaces for lowand high-temperature chip heating in briquetting lines is proved. Thermal efficiency of such furnaces when dispersed materials heating is much higher than drum or feed-through furnaces. Hot briquetting of shavings reduces the pressing force, which reduces the specific energy consumption. The use of rotary kilns can reduce technological operations and equipment of production sites for the manufacture of briquettes

Light Metals Chips Recycling by Plastic Consolidation

In this work, hot extrusion of light metal scraps as a new way of plastic consolidation will be presented. This kind of material recovering is a promising alternative for conventional recycling processes. Nowadays discards from machining of semi-finished products are being recycled throughout re-melting processes. However, due to its significant susceptibility to oxidation most of the chips and scraps are burnt during the melting process. It has been already recognized that aluminum losses connected with this operation can reach from 40% to 50%. A technology that has been presented in this work combines cold compaction and hot extrusion of 413.0 aluminum alloy scraps. It was found that quality of as-extruded rods depends strongly on extrusion conditions. Higher extrusion speed leads to higher quality of rods surface. Additionally brittle Si and Al-Fe-Si particles increases overall mechanical properties in comparison to its industrial counterpart.

Fracture Analysis and Mechanical Property of AZ91D Magnesium Alloy Chips Prepared by Solid State Recycling

AZ91D magnesium alloy is prepared by hot extrusion of recycled machined chips and its fractures and mechanical properties are investigated at various extrusion conditions. Cold-press is employed to prepare extrusion billets of AZ91D magnesium alloy chips, and then the billets are hot extruded at 573K-723K with an extrusion ratio of 11:1. The results show that tensile strength and elongation of the extrusion magnesium alloy with the extrusion temperature of 673K and the extrusion rate of 0.08mm/s can reach 380MPa and 6%, respectively. Fracture surface presents a mix mechanism of dimple-like fracture and gliding fracture. Due to grain refinement by cold-press and hot extrusion, mechanical properties of extruded rods are much higher than those of as-cast AZ91D magnesium alloy. Also, much lower energy consumption is necessary for this recycling compared to the conventional casting process. Solid state recycling is an efficient method for magnesium alloy chips recycling.