Encontrados 23 documentos, a visualizar página 1 de 3

Liquid crystal displays as secondary resources for Indium recovery: characteriz...

End-of-life liquid crystal display (LCD) monitors represent an important emerging flow in electric and electronics waste, which require urgently appropriate technologies for its management. These devices have environmental issues that discourage its treatment trough incineration or disposal. Moreover, the LCD-glass component has in its composition an important and strategic metal, indium, whose recycling is ess...

End-of-life Zn–MnO2 batteries: electrode materials characterization

Physical and chemical characterization of several sizes and shapes of alkaline and saline spent Zn–MnO2 batteries was carried out, aiming at contributing for a better definition of the applicable recycling processes. The characterization essays included the mass balance of the components, cathode and anode elemental analysis, the identification of zinc and manganese bearing phases and the morphology analysis of...

Characterization of Spent Ni-MH Batteries

Spent Ni-MH batteries are not considered too dangerous for the environment, but they have a considerable economical value due to the chemical composition of electrodes which are highly concentrated in metals. The present work aimed at the physical and chemical characterisation of spent cylindrical and thin prismatic Ni-MH batteries, contributing for a better definition of the recycling process of these spent pr...

Recycling of exhausted batteries and EAF dusts by leaching with several aqueous...

Zinc is a base metal present in several products of general use, and therefore found in numerous residues and end-of-life products. The two main sources of zinc containing wastes are spent Zn-MnO2 portable batteries and electric arc furnace (EAF) dusts from steelmaking plants. The recovery of metals from these residues by appropriate recycling processes is mandatory due to environmental, economic and resource c...

Soda and aluminum recovery from spent etching baths by aqueous precipitation

The aluminum anodising industry is an important industrial sector that produces great amounts of polluted effluents, which after treatment generate sludge. This fact brings environmental and economical concerns to the companies. Best way to deal with the problem, according to the “prevention strategy” set by the European Directive on Integrated Pollution Prevention and Control, is to implement preventive techni...

The effect of shredding and particle size in physical and chemical processing o...

Circuit boards present in most electric and electronic devices are very important components, which should be removed during sorting and dismantling operations in order to allow further adequate treatment for recovering valuable metals such as copper, nickel, zinc, lead, tin and rare elements. This recovery can be made by physical and chemical processes being size reduction by shredding the first step. In this ...

Valorisation of rice husk by chemical and thermal treatments 

In the industrial production of rice, large quantities of rice husk are generated constituting a residue with costs for the companies, which must be appropriately managed. The high grade of silica in the rice husk opens a possibility for its valorisation, through the production of amorphous silica with high porosity and potential application as ligand in construction materials, as catalyst support, as metals ad...

Battery recycling by hydrometallurgy : evaluation of simultaneous treatment of ...

A research work has being carried out aiming at evaluating the possibility of treating simultaneously several electrochemical systems of spent batteries using the same process, in order to overcome the high costs and difficulties of selective collection and sorting. Zn-MnO2 systems, representing more than 75% of portable battery market, shall be treated in dedicated processes. The treatment assessment using a s...

Production and characterisation of amorphous silica from rice husk waste

Rice covers about 1% of the earth’s surface. Rice husk is the major by-product of the riceprocessing industries which must be appropriately managed. On average 20% of the rice paddy is husk. The major constituents of rice husk are cellulose, lignin and silica. During growth, rice plants absorb silica and other minerals from the soil and accumulate it into their structures. Its composition varies with the divers...

Reciclagem de materiais : Uma necessidade premente para o desenvolvimento global