Method for processing starting materials for recycling

Abstract

A method of treating recyclable raw materials containing valuable metals is provided, the method including the steps of: feeding recyclable raw materials (W) containing valuable metals into a rotary kiln furnace (2) in which a refractory product having an Al 2 O 3 -Cr 2 O 3 content of 70% or greater is used for an inner wall; feeding an additive (A) containing SiO 2 as a major component into the rotary kiln furnace (2) so as to increase a viscosity of a slag (S) flowing along the inner wall, thereby the recyclable raw materials (W) are attached on the slag (S) having a high viscosity such that at least part of the recyclable raw materials (W) is exposed to the inside of the rotary kiln furnace; and burning / melting the recyclable raw materials (W) attached on the slag (S) in the rotary kiln furnace (2).

Description

technical field [0001] The present invention relates to a system for recycling raw materials such as waste electronic components or waste electronic substrates containing valuable metals (Cu, Au, Ag, Pt, Pd, etc.) by burning and melting them in a rotary kiln and recovering the valuable metals Methods of processing recycled materials. [0002] This application claims priority based on Japanese Patent Application No. 2013-130943 for which it applied in Japan on June 21, 2013, and uses the content here. Background technique [0003] Wastes such as electronic substrates, flexible substrates, IC chips, mobile phones, PCs and other electronic equipment, household appliances such as refrigerators, and automobiles contain flammable resin materials, etc., and iron (Fe) and aluminum (Al) and Other valuable metals include copper (Cu), gold (Au), silver (Ag), platinum (Pt), palladium (Pd), and the like. Therefore, it is proposed to recycle these wastes as recycling materials. [0004...

AI Technical Summary

Problems solved by technology

[0014] In the method of Patent Document 1, bricks (refractory material) are easily worn out (abrasive) due to rapidly flowing slag

In addition, due to the high fluidity of the slag, the entire recycled raw material introduced into the rotary kiln may be soaked or buried in the slag, and the contact between the recycled raw material and the combustion air is hindered, and the combustion of the recycled raw material becomes difficult. Stablize

[0015] Specifically, the reused raw material and the solidified slag around it are discharged out of the furnace without being fully burned or melted, or the temperature in the furnace changes suddenly due to sudden combustion during the flow in the furnace, which may affect the processing efficiency

[0016] In addition, refractory materials such as bricks made of basic magnesia-based refractory materials mainly composed of MgO have relatively low hardness. It is easy to wear due to friction, so it is not suitable for the treatment of recycled materials such as waste substrates

[0017] In addition, in the method of Patent Document 2, the brick (refractory material) composed of the basic magnesia-based refractory material mainly composed of MgO is embrittled (cured) due to moisture, and may be easily worn out.

[0018] And, in the method of patent document 3, the shape of reuse raw material does not change too much before and after processing, therefore needs to carry out crushing etc. to adjust shape with crusher etc. in pre-process or post-process, processing cost (crushing cost ) increase

[0019] In addition, as in Patent Documents 1 to 3, in the method of installing a combustion furnace in a rotary kiln and burning the combustion furnace when processing the recycled raw material, thereby heating and burning and melting the recycled raw material, there is a possibility that the The combustion flame of the furnace, the bricks (refractory material) are locally heated and lost

In addition, fuel costs (operating costs) such as heavy oil and gas used to burn the combustion furnace increase

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