The process of classifying scraps, scraps and unqualified products generated during the processing and manufacturing of iron materials or titanium products, and processing them into reusable qualified furnace materials. It is one of the preparation processes of titanium materials. Residual material can be divided into block material and chip material according to geometric shape. The processing technology of block material is relatively simple. In the late 1960s in the United States and China in the late 1970s, the processing technology and recycling methods of bulk materials have been solved successively. The processing technology of chip material is relatively complicated, and the difficulty is how to separate the high-density cemented carbide tip fragments, iron chips and oxide chips mixed therein. Before this problem was solved, titanium chips were mainly used for downgrade, that is, processed into titanium dioxide for pigments and alloy additives for steel making and aluminum making, such as titanium-iron or titanium compacts. At the end of the 1970s, European and American countries treated the remnants into return materials that met the requirements of remelting and could be recycled. China also solved this problem in the early 1980s.
Types are divided into lump material processing technology, crumb material processing technology and the recovery of other residual materials.
Lump material processing technology mainly includes brand identification, cutting ruler and surface treatment. Use simple spectrometer, portable spectrometer with microcomputer, x-ray instrument, thermoelectric potential comparator and other instruments to quickly identify the grade of the bulk material on the spot. The proportion of random inspection can be determined according to the management status and use requirements of residual titanium. Lump materials that do not meet the size requirements should be cut. The flame cutting method can be used to cut large pieces of material, and other sizes of materials can be cut to length with hydraulic shears, combined punching shears, shears, grinding wheel cutting machines and other equipment. The bulk residues generated by hot processing should remove the surface scale and oxygen-rich layer; the residues of cold processing should remove the surface oil stains with a degreaser.
Crushing material treatment process mainly includes primary selection (including removal of oxidized scraps), crushing, cleaning, drying, classification, and removal of high-density inclusions. First select the obvious visible dissimilar metal or non-metallic inclusions with the naked eye, and then select the ferromagnetic materials mixed in with the general magnetic separator. Use a hammer crusher to crush long chips for later processing and use. The oil stains on the titanium shavings are removed with organic or inorganic metal degreasing agents in a continuous washing machine, and then dried by a continuous dryer, and the particle size of the shavings is controlled within a certain size by a sieving machine or shaker. Other means to further remove weak magnetic or non-magnetic high-density inclusions. X-ray inspection of special purpose scraps to determine whether the high-density inclusions meet the requirements.
Recovery of other residual materials After the residual materials are processed, they can be mixed with sponge titanium and pressed into a vacuum wasted electrode for remelting. Bulk materials should not be mixed with sponge titanium, and can be directly welded into consumable electrodes for smelting; block materials below medium size (70mm × 70mm × 70mm) can use vacuum non-consumable electric arc furnace, electron beam furnace and Plasma furnace and other remelting recovery. Residues that do not meet the conditions for remelting return materials can be used as alloy additives for steelmaking and aluminummaking or for other purposes. Recycling of residual materials can obtain obvious economic benefits. According to the statistics of the former Soviet Union and China, when the ingot is smelted, the cost of the ingot can be reduced by every 1% increase in the amount of return material added. 7% ～ 0.89%. If 30% of the return material is added to the raw material, the ingot cost can be reduced by 21% ～ 26.7%.
We are studying other methods for recovering titanium material residues, such as electrolysis, induction slag method, powder metallurgy and other new methods. In order to better inspect and remove high-density inclusions in the chips, an automatic x-ray fluorescent machine inspection production line is being developed. The device can not only detect high-density inclusions online, but also remove them automatically with vacuum suction tips after the inspection. In order to completely eliminate the source of carbide tips in titanium residues, high-speed steel tools are used for the machining of titanium materials and titanium products.
Titanium Material Residue Processing
