Cadmium tellude preparation method

Abstract

The invention provides a cadmium tellude preparation method, which comprises steps of primary synthesis and secondary synthesis. The primary synthesis comprises the steps: putting tellurium and cadmium which are arranged in a staggered and up-and-down manner into a first graphite boat in a layered manner, putting the first graphite boat in a first quartz tube, and then placing the first quartz tube in a first synthesis furnace; filling first protective gas to discharge air in the first quartz tube; conducting three-section temperature increment, filling the first protective gas into the first section, and filling a first reducing gas into the second and the third section; filling the first reducing gas after the completion of synthesis reaction, and cooling down to an room temperature; and obtaining a first synthetic product. The secondary synthesis comprises the steps: putting the first synthetic product into a second graphite boat after being crushed, placing the second graphite boat into a second quartz tube, and placing the quartz tube into a second synthesis furnace; filling a second protective gas to discharge air in the second quartz tube; conducting two-section temperature increment, filling the second protective gas into the first section, and filling a second reducing gas into the second section; and after the completion of synthesis reaction, stopping heating, filling the second reducing gas, cooling down to the room temperature, so as to obtain a second synthetic product. Due to adoption of the method provided by the invention, the raw materials can be prevented from oxidation and being in contact with poisonous substances.

Description

technical field [0001] The invention relates to a preparation method of synthetic materials, in particular to a preparation method of cadmium telluride. Background technique [0002] At present, most of the preparation methods of cadmium telluride are synthesized by mixing cadmium powder and tellurium powder. Among them, the Chinese patent CN1380246A authorized and announced on November 20, 2002 discloses a preparation method of cadmium telluride powder. The method uses cadmium powder and tellurium powder are synthesized in a crucible under vacuum conditions, and after the synthesis, they are ground and annealed; Chinese patent CN101125679A, which was authorized and announced on February 20, 2008, discloses a method for preparing high-purity cadmium telluride. The method is to combine 5N tellurium and 5N cadmium is mixed according to the molar ratio of 1:1, and the mixture is crushed or ground into pellets. This method will increase the probability of cadmium powder oxidatio...

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Problems solved by technology

[0002] At present, most of the preparation methods of cadmium telluride are synthesized by mixing cadmium powder and tellurium powder. Among them, the Chinese patent CN1380246A authorized and announced on November 20, 2002 discloses a preparation method of cadmium telluride powder. The method uses cadmium powder and tellurium powder are synthesized in a crucible under vacuum conditions, and after the synthesis, they are ground and annealed; Chinese patent CN101125679A, which was authorized and announced on February 20, 2008, discloses a method for preparing high-purity cadmium telluride. The method is to combine 5N tellurium and 5N cadmium is mixed according to the molar ratio of 1:1, and the mixture is crushed or ground into pellets. This method will increase the probability of cadmium powder oxidation during the process of mixing or grinding into pellets, and also increases the operator’s exposure to The probability of cadmium powder, so there is a certain degree of harm to the human body. At the same time, if cadmium powder is used to synthesize cadmium telluride, cadmium powder is easy to oxidize, and the cost of producing cadmium powder is relatively high; China’s authorized announcement on June 16, 2010 Patent CN101734630A discloses a method for preparing high-purity cadmium telluride. The method is to place 5N cadmium material and 5N tellurium material in a closed quartz tube after carbon coating, and divide cadmium material and tellurium material into 1:1.1~1.15 respectively. N-1 parts and N parts are alternately placed in the quartz tube, and the tellurium material is placed first and last. After deoxidation, the method of high temperature and high pressure is used for synthesis. Since the conditions of this method are high temperature and high pressure, there is a certain danger in the synthesis process. , the output is relatively small, and the cost of industrialization is relatively high

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