Method for preparing N-type Bi2Te3 based thermoelectric materials by refrigeration crystal bar processing waste

Abstract

The invention relates to a method for preparing N-type Bi2Te3 based thermoelectric materials by refrigeration crystal bar processing waste. The technical scheme includes that firstly, the refrigeration crystal bar processing waste is grinded, washed and dried, secondly, dried powder is placed into a gas reduction furnace, mixed gas of reducing gas and inert gas is led in, the gas reduction furnace is heated up to reach 200-550 DEG C, the temperature is kept for 1.0-5.0h and is reduced to room temperature, and the refrigeration crystal bar processing waste with impurities removed is obtained. The refrigeration crystal bar processing waste with the impurities removed is placed into a quartz tube, and according to the chemical formula (BixSb2-xTe3-ySey, wherein 1.5<=x<=2.0 and 0.1<=y<=0.7) of the N-type Bi2Te3 based thermoelectric materials, Bi, Te, Sb and Se raw materials with purity higher than 99.9wt% are added. Finally, the quartz tube is packaged in an evacuated manner and is smelted in a heating furnace at the temperature of 580-850 DEG C, the temperature is kept for 0.5-5.0h, the quartz tube is cooled along with the furnace, and an alloy ingot in the quartz tube is taken out, so that the N-type Bi2Te3 based thermoelectric materials are obtained. The method has the advantages of simple process, short recovery cycle, less environmental pollution and low cost.

Description

technical field [0001] The present invention belongs to N-type Bi 2 Te 3 Based thermoelectric materials technology field. Specifically relates to a method of preparing N-type Bi by using refrigeration crystal bar processing waste 2 Te 3 approach to thermoelectric materials. Background technique [0002] Thermoelectric material is a functional material that can directly convert heat energy and electric energy, and it has attracted more and more attention in today's society. Bi 2 Te 3 As the thermoelectric material with the best thermoelectric performance near room temperature, the base compound has an irreplaceable position in the process of commercial application and is widely used in the semiconductor refrigeration industry. Bi is currently commercially produced on a large scale 2 Te 3 Based thermoelectric materials are usually uniaxially grown, such as Bridgman method and zone melting method, in order to obtain Bi with excellent thermoelectric properties. 2 Te 3...

AI Technical Summary

Problems solved by technology

The Bi obtained by the above production method 2 Te 3 The mechanical processing performance of the base cryogenic ingot is poor, and it is easy to break and break in the subsequent processing process, the scrap rate is high, and the material utilization rate is less than 50%.

The theoretical basis of using the above method to extract Te and Bi is to oxidize the Te or Bi element, and then separate and purify it separately, and the recovery scheme is to separate and purify the valuable elements in the refrigeration ingot processing waste, which is divided into multiple steps and multiple steps. The process gradually separates and purifies individual elemental elements. The process is complicated, the cycle is long, the environment is polluted seriously, and the production cost is high.