Ingots, finished scraps of processed materials, and remnants of cold-processed products (such as feed heads, process wastes, etc.) can be recycled into ingots by two electron beam smelting.
Purification treatment: residual materials generated in the process of pressure processing are mainly contaminated by coolant and lubricant, which can be cleaned with organic solvents such as alkali, acetone or alcohol, or washed with high-efficiency detergent (neutral or slightly alkaline). Washing can be done in a rotary washing machine. Wash with water until neutral and oil-free. The residual materials after washing are dried by air, and then dried in the electric drying box, drying at 70~80℃ for 3~4 hours.
Preparation of material bar: different preparation methods are adopted according to the shape and size of the residual material after surface purification. For the large residual material, the residual material is bound after shearing, and then welded in the argon arc welding box. The chips and slender chaff can be moulded and pressed on an oil press to make a pressing block with unit pressure of 8×107~l×l08Pa, and the density of the pressing block is 60%~70% of the theoretical density. As the elasticity of tantalum residue is larger than that of niobium residue, it is generally required to be fed and prepressed in batches for 2-3 times, and then it is generally pressed into shape. Niobium shavings can be pressed into a single feed. The pressing block is welded into the material bar of the required specification in the argon arc welding box, which is the reinforcing material bar, and can lap the welding board edges between the cross section joints.
The tantalum and niobium residues contaminated by chemical impurities are generally recovered by hydrogenation. The hydrogenation process is to use tantalum and niobium to absorb hydrogen at a certain temperature to produce hydrogen embrittleness, change the bulk residue into powder hydride, and then make tantalum powder or niobium powder after acid washing (hydrochloric acid or hydrofluoric acid aqueous solution) and dehydrogenation. Such as the chemical composition of metallurgical grade tantalum powder, niobium powder can be used as tantalum, niobium processing materials.
