Comparison of ultrasound-assisted and traditional caustic leaching of spent cathode carbon (SCC) from aluminum electrolysis

(Co-)combustion behaviors and products of spent potlining and textile dyeing sludge

Detoxification of spent cathode carbon blocks from aluminum smelters by joint controlling temperature-vacuum process

Co-treatment of spent cathode carbon in caustic and acid leaching process under ultrasonic assisted for preparation of SiC.

Co-utilization of spent pot-lining and coal gangue by hydrothermal acid-leaching method to prepare silicon carbide powder

Spent potlining (SPL) from Hall-Heroult cells is a kind of toxic solid waste with recyclable carbon and electrolyte. The recycle of SPL by floatation, which can meet environment requirements and bring economic profits, is focused on presently because of its great potential to be industrialized and spread. However, it is difficult to get a good floatation index in floatation of SPL with carbon content lower than 50%. Therefore, the dressing of SPL with 36.1% of carbon has been investigated in the paper with the interesting potential to improve the quality of floatation products by optimizing floatation conditions, such as grinding size, pulp density and agitation speed of floatation machine. And the comparative experiment has been performed. The results show that quality of both carbon product and electrolyte product were improved under optimized conditions of grinding size of 90% of the particle sizes less than 0.74mm, pulp density of 25% and agitation speed of 1700r/min. The carbon content in carbon product was raised by 5.40 and carbon content in electrolyte product decreased by 0.26 while electrolyte recovery of electrolyte product increased by 4.58.

Recycle of Spent Potlining with Low Carbon Grade by Floatation

The use of powder materials in smelting process has some impact on the breathability of the burden, and it ultimately results in poor production and quality of industrial silicon. If pelletizing is prepared by these powder materials, it not only reduces production cost but also reuses waste effectively. It could protect forest resources productively and contributes to sustainable development if charcoal is replaced by pelletizing using as carbonaceous reducing agent. Different powders such as anthracite fine, petroleum coke powders, charcoal powders, silica fume have been produced in the production process of industrial silicon. Briquetting of these powders with a binder starch D was voted into submerged arc furnace not only utilizes the resources sufficiently, but also reduces the production costs. Effects of content of starch D as binder and CaO as pore former on compressive strength, the shatter strength, the heat intensity and porosity of pelletizing were investigated in this paper. The following results were got: first, the performances of pelletizing except porosity were excellent when starch D was used as binder; second, CaO could efficiently improve porosity, and the pelletizing could satisfy requirement of industrial silicon production.

The Research on Effects of Different Binders on Performances of Carbonaceous Pelletizing in Industrial Silicon Production

Cold ramming paste was synthesized with electro-calcined anthracite (ECA) and artificial graphite as an aggregate and furan resin as a binder. Properties of synthesized paste were investigated by Universal Testing Machine, thermogravimetry (TG) and gas chromatography (GC) mass spectrometry (MS). The results show that the synthesized paste is an ecofriendly material and that it has some superior physical properties such as low electrical resistivity, high compressive strength, appropriate sodium penetration, and thermal expansion, all of which can meet industry requirements. The TG curve of the paste can be divided into three stages and the lower heating rate should be used in the second stage. Moreover, the resin functional groups disappear more completely at higher carbonized temperature based on infrared (IR) spectrum analysis.

Ecofriendly Cold Ramming Paste for an Aluminum Electrolysis Cell with Furan Resin As a Binder

In this paper, the standard entropy, heat capacity at constant pressure, standard enthalpy and standard Gibbs free energy of formation are estimated by application of two-parameter model. The model is relatively simple, accurate and practical. Based on the thermodynamic data for related pure compositions are reported, the five possible chemical reactions in the Cu2O-In2O3 system are studied in the process of preparation CuInO2 by solid reaction method. The relations between equilibrium constant and temperature is plotted. The curves of -T and lgK-1/T for the chemical reactions in the system have also been fitted. The results show that the Cu2O is easy to be oxidized into CuO, which reacts with In2O3 to yield Cu2In2O5 at lower temperature. However, the CuInO2, which is prepared from the Cu2O-In2O3 system, is oxidized into Cu2In2O5 easily in the oxygen atmosphere. The reaction of preparing CIO was reversible and incomplete. Therefore, preparation CIO is very difficult by solid reaction method whether in atmospheric pressure or isolated air and gas shield conditions, because K1 >-40kJ/mol.

Thermodynamic Study on CuInO2 Preparation by Solid Reaction Method

A cold ramming paste for aluminum electrolysis cells was synthesized with electro-calcined anthracite and artificial graphite as aggregate and phenol–formaldehyde resin as binder. The synthesized pastes were characterized by thermogravimetry, infrared spectroscopy, scanning electron microscopy–energy dispersive spectroscopy, and gas chromatography–mass spectrum. The results show that the synthesized cold ramming paste is an ecofriendly material and it has some superior physical properties, such as low electrical resistivity, high compressive strength, appropriate sodium penetration, and thermal expansion, all of which can meet industry requirements. The mass loss (3.4%) and linear shrinkage reach the maximum during the third stage (from 360 to 600 °C) based on thermal analysis, so a lower heating rate should be used in this stage. Moreover, the resin functional groups disappear more completely at higher carbonization temperature.

Rong Xing Li

Papers

Recycle of Spent Potlining with Low Carbon Grade by Floatation

The Research on Effects of Different Binders on Performances of Carbonaceous Pelletizing in Industrial Silicon Production

Ecofriendly Cold Ramming Paste for an Aluminum Electrolysis Cell with Furan Resin As a Binder

Thermodynamic Study on CuInO2 Preparation by Solid Reaction Method

A More Ecofriendly Cold Ramming Paste for an Aluminum Electrolysis Cell with Phenol–Formaldehyde Resin As Binder