TWI496896B - Recovery method of copper - free indium gallium selenium residue by heat treatment - Google Patents

Description

Method for recovering heat-treated copper indium gallium selenide residual target

The invention relates to a method for recovering a heat-treated copper indium gallium selenide residual target, in particular to a method for oxidizing roasting of copper indium gallium selenide (CIGS) through a process such as crushing, sieving, oxidizing roasting and dissolving. Oxidizing atmosphere, the chalcopyrite structure is partially decomposed into oxidized metal, and the evaporated oxidized selenium vapor can be enriched by condensation. The remaining indium oxide, gallium oxide and copper selenate can be recovered and concentrated by sulfuric acid, and dissolved. In the process, the copper indium gallium ion aqueous solution can be completely dissolved without using heating and a large amount of oxidizing agent, and the CIGS powder can be prepared again, thereby recovering the residual target of CIGS, thereby achieving the purpose of sustainable resources.

Both copper indium selenide (CIS) and copper indium gallium selenide (CIGS) are I-III-VI ₂ compound semiconductors, due to their high photoelectric efficiency and low cost materials, and the photocracking effect of amorphous germanium thin film solar cells (Staebler Compared with the -Wronski effect, the stability and radiation resistance of copper indium gallium selenide (CIGS) photovoltaic elements are favored. If compared with cadmium telluride (CdTe) solar cells, CIGS materials have no toxic pollution problem of cadmium. Also more friendly.

At present, the thin film solar cell multilayer film group is mostly prepared by sputtering, so the spoiling target quality directly affects the properties of each film layer, so the target production research and technology is the most critical process, compared with the evaporation method, the sputtering method The method has many advantages, such as (1) composition control is easy; (2) the film has high density, and the adhesion is several times that of the evaporation method; (3) the raw material utilization rate is high, and the film is not required to be shielded. , can reduce the pollution of the vacuum chamber; (4) uniformity of the film Good, suitable for large-area production; however, the use of target materials in the production of copper indium gallium selenide (CIGS) thin film solar cells by sputtering is only about 30%, plus indium gallium metal is a rare precious metal. Therefore, about 70% of the residuals still need to be recycled. Therefore, many domestic and foreign upstream and downstream targets are used and recycled and remanufactured, which has become one of the key technologies for sustainable development at home and abroad.

According to the world and US patents, a few have proposed CIS/CIGS membrane group recycling projects, and there is no CIS/CIGS recycling related research in academic papers. Nowadays, many scholars have studied the corrosion of chalcopyrite structure CuFeS ₂ . By adding ferric chloride to reduce copper, other scholars use sodium chloride and sulfuric acid to attack copper. However, to destroy the chalcopyrite structure of the thermodynamically stable phase and dissolve it in solution, it is often at low pH. In addition to the environment and the addition of a large amount of oxidant, high recovery rate can be achieved; in addition, Ag ₂ Se is heat-treated through the atmosphere (300 ° C - 650 ° C) for the purpose of making the structure looser and transparent. Partial pressure is used to form Ag metal and SeO ₂ ; otherwise, after dissolving CIS with nitric acid, the elements of Cd, Cu and Se are separated by electrolysis, and then the oxide is formed by oxidation and distillation, and the dissolved solution of ZnO/InO after electrolysis is completed. A ZnO/InO mixed powder was formed by distillation.

The main object of the present invention is to provide a low-cost, simple and high-recovery CIGS residual target recovery process for directly converting waste residual target into high-priced CIGS nano powder for heat treatment of copper indium gallium selenide residual target. method.

In order to completely dissolve the copper indium gallium selenide residual target in the solution, thereby obtaining high recovery rate, the CIGS is partially oxidized by preheating in air, and then dissolved into metal ions by using sulfuric acid, which can be further This filtrate was converted to a high monovalent CIGS nanopowder.

The invention can oxidize copper indium gallium selenide residual target by heat treatment in air, and At this stage, the volatile matter of selenium is generated, and the gas is separated into the wall of the normal temperature and condensed into solid selenium, and then the remaining metal oxide is dissolved into the metal cation solution by the dilute sulfuric acid solution, and the dissolution recovery rate is up to 99%. The obtained copper indium gallium ion aqueous solution can still be used as a pre-displacement solution for preparing CIGS nano powder, and can be converted into CIGS nano powder by a thermal heating up method.

The invention only needs to be calcined and heat-treated in air at 400-600 ° C for selenium removal, and then acid etching with sulfuric acid. Since the process is simple and the recovery rate is up to 99%, the cost can be greatly reduced, the value of the recovered product can be increased, and the resource can be achieved. The purpose of sustainable use.

The method for recovering the heat-treated copper indium gallium selenide residual target is as follows: the copper indium gallium selenide residual target is ground and sieved, and the ground metal powder after grinding is placed in a furnace for heating at 400-600 °C air calcination heat treatment to remove selenium, the quaternary target copper indium gallium selenide is converted into copper indium gallium powder and selenium gas, and the selenium gas is separated into the reducing liquid through the reactor to obtain elemental selenium; The powder is added with sulfuric acid for acid etching, so that the copper indium gallium powder is completely dissolved in the sulfuric acid solution to form an aqueous solution of copper indium gallium ion; the copper indium gallium ion aqueous solution can be used as a precursor solution for preparing copper indium gallium selenide powder, and then The thermal heating method converts the aqueous solution of copper indium gallium ions into copper indium gallium selenide nano powder.

The method for recovering a heat-treated copper indium gallium selenide residual target according to the present invention, wherein the concentration of the sulfuric acid is 1M.

The method for recovering the heat-treated copper indium gallium selenide residual target of the present invention, wherein the baking temperature ranges from 400 ° C, 500 ° C and 600 ° C, and the temperature is maintained for one to three hours.

The method for recovering a heat-treated copper indium gallium selenide residual target according to the present invention, wherein the furnace has an air flow rate of 50 ml to 1000 ml.

The method for recovering a heat-treated copper indium gallium selenide residual target according to the present invention, wherein the etching temperature is from 80 ° C to 160 ° C for a period of from one hour to four hours.

The method for recovering the heat-treated copper indium gallium selenide residual target of the invention has the advantages that the recycling process is simplified, the process is simplified compared with the traditional conversion CIGS for the one-metal metal, the recycling cost is low, and the conversion is CIGS nanometer. The resource-added products of powder have high added value and can achieve the purpose of sustainable use of resources.

The first figure shows the metal recovery rate directly by 1M sulfuric acid etching in the embodiment of the present invention.

The second figure is a flow chart of the recycling method of the embodiment of the present invention.

The third figure shows the thermogravimetric-thermal difference analysis of the CIGS residual target of the embodiment of the present invention.

The fourth figure shows the X-ray diffraction pattern after baking at 400 ° C in the embodiment of the present invention.

The fifth figure shows the X-ray diffraction pattern after baking at 500 ° C in the embodiment of the present invention.

The sixth figure shows the X-ray diffraction pattern after baking at 600 ° C in the embodiment of the present invention.

The seventh figure shows the metal recovery rate of 1 M sulfuric acid after roasting at 400 ° C in the embodiment of the present invention.

The eighth figure shows the metal recovery rate after 1500 sulfuric acid etching after baking at 500 ° C in the embodiment of the present invention.

The ninth graph shows the metal recovery rate after 1600 sulfuric acid etching after being calcined at 600 ° C in the examples of the present invention.

The tenth figure shows the crystal phase analysis chart and elemental analysis chart of the single nano powder obtained after heat treatment of the product of the embodiment of the present invention.

The present invention is directed to a preferred and practical embodiment for the purpose of the above-mentioned purposes and functions, and is illustrated in the following drawings. The present invention details the following: The present invention recovers high-density copper-indium gallium selenide. In the process of residual target, firstly, the block is ground into a powder, and after 200 mesh screening, a relatively uniform powder diameter is obtained, and placed in a tubular furnace, and baked in an oxidizing atmosphere at 400 ° C - 600 ° C for one to four hours, in different The amount of selenium removed is obtained under calcination conditions, and the calcined powder is dissolved in 1 M dilute sulfuric acid, wherein the ratio of powder to sulfuric acid is about 1 g: 0.2 L, and the reaction is carried out at a suitable temperature (25-100 ° C) to obtain CIG. The ion clarified filtrate is used as a precursor solution for synthesizing CIGS nanopowder, and then CIGS nanopowder powder can be obtained by a thermal heating method.

Explain the case and implementation effectiveness

According to the technology applied by the present invention and the effect of the reachability, the implementation parameters are as follows:

Case 1: In the process of recovering high-density copper-indium gallium selenide residual target, the block is ground into powder, and after 200 mesh screening, a relatively uniform powder diameter is obtained, which is directly placed in a sulfuric acid concentration of 1 M. The ratio of powder to sulfuric acid is about 1g: 0.2L, and the reaction is carried out at a temperature of 60-100 ° C for one to four hours. The recovery of the filtrate after the reaction is as shown in the first figure, and the analysis results indicate the individual recovery rate of copper indium gallium. It will increase with the increase of temperature and time. However, after 100 °C longer etching time, it can not be completely recovered. It can be found that selenide is not a highly efficient treatment technology through general acid etching.

Case 2: In this embodiment, the CIGS residual target after sputtering is subjected to acid etching, after being pulverized and sieved, heat-treated at different baking temperatures (400 ° C, 500 ° C and 600 ° C), and the calcined powder is measured. The composition analysis is shown in Table 1. The second figure shows the flow chart of the overall CIGS residual target recovery method. The third figure shows the result of the thermogravimetry-thermal difference analysis (TG-DTA) of the CIGS powder. At 350 °C, the exothermic peak is CIGS phase change to CIS, and there is constant weight loss (~5%). When the temperature rises to 500 °C, the weight loss increases significantly to 15%, indicating that Se is continuously oxidized in CIGS. The weight loss caused by SeO ₂ is shown in the fourth figure as the X-ray diffraction pattern of the powder after calcination at 400 ° C. After oxidation heat treatment, CuInSe ₂ , In ₂ O ₃ , Cu ₉ Ga ₄ and CuIn ₃ Se _{5 are obtained} . The fifth phase shows the X-ray diffraction pattern after calcination at 500 ° C. After higher temperature treatment, the phase components are Cu ₂ SeO ₄ , In ₂ O ₃ , CuInSe ₂ , CuSe and Ga ₂ O _{3 .} , as shown in FIG sixth through X-ray diffraction lines of FIG. 600 ℃ high temperature of the obtained, which is obtained _{Cu 2 SeO 4, In 2 O} 3, and Ga ₂ O ₃ Displayed after calcined at different temperatures, copper indium gallium which are varying degrees of oxidation.

When the powder is calcined at different temperatures, it is placed in 1M of dilute sulfuric acid for acid etching. The recovery rate is shown in the seventh, eighth and ninth diagrams. It can be seen that after calcination at 500 °C, it is etched with 1M sulfuric acid. The maximum copper indium gallium recovery rate can be achieved in two hours.

Case 3: In this example, the sulfate (copper sulfate, indium sulfate and aqueous solution of gallium sulfate) obtained in the second case is used as a starting material, and dried at 150 ° C to form a sulfated metal salt before the preparation of the metal complex, followed by Add octadecylamine to the metal salt, dissolve at 150 ° C for 1 hour, add octadecylamine and selenium powder (4.2 mmol) to a three-necked flask, and add the metal complex to this mixture. After the solution, the reaction was heated to 130 ° C for one hour, and then the reaction was heated to 250 ° C for one hour. After the reaction was completed, the temperature was lowered to 80 ° C, and 25 ml was added. The reaction was terminated by ethanol, and then the powder was obtained by centrifugation at 6000 rpm for 5 minutes in a centrifuge, and then the by-product was washed and removed by using ethanol and n-hexane repeatedly, and finally the powder was dispersed in n-hexane and centrifuged at 6000 rpm for 20 minutes to separate. A nano powder with good dispersibility.

The octadecene (ODE) is added to replace the volume of the oleylamine solvent, and by adding an excess selenium content Se/(Cu+In+Ga)=4, and holding the temperature at a reaction temperature of 250 ° C for one hour, The powder was obtained by centrifugation at 6000 rpm for 5 minutes, and then the by-product was washed and removed by using ethanol and n-hexane repeatedly. The powder was finally dispersed in n-hexane and dried at room temperature until overnight, and the produced nano-selenium was produced. The results of the analysis of copper indium gallium powder are shown in the tenth figure.

In view of the above, the present invention has achieved the intended use and efficacy, and is more desirable and practical than the prior art, but the above embodiments are only specifically described for the preferred embodiment of the present invention. The present invention is not intended to limit the scope of the invention, and all other equivalents and modifications may be included in the scope of the invention covered by the invention.

Claims (1)

A method for recovering a heat-treated copper indium gallium selenide residual target, the steps of which are as follows: the copper indium gallium selenide residual target is ground and sieved, the sieved sieve is 200 mesh, and the sieved metal powder is placed Heating in a furnace, heat-treating at 400-600 ° C in air for selenium removal, the furnace is passed through an air flow of 50 ml to 1000 ml, and the optimum temperature for the calcination is 500 ° C, and the temperature is maintained for one to three hours, The quaternary target copper indium gallium selenide is converted into copper indium gallium powder and selenium gas, and the selenium gas is separated into the reducing liquid through the reactor to obtain elemental selenium; and the calcined powder is added to sulfuric acid for acid etching and dissolution. The concentration is 1M, and the etching temperature is 80° C.-160° C. for one hour to four hours, so that the copper indium gallium powder is completely dissolved in the sulfuric acid solution to form an aqueous solution of copper indium gallium ion; the aqueous solution of copper indium gallium ion It can be used as a precursor solution for preparing copper indium gallium selenide nano powder, and then convert the copper indium gallium ion aqueous solution into copper indium gallium selenide nano powder by a thermal heating method.