TW202100760A - Method for recycling palladium-containing waste including a pre-treatment step, an aluminum recovery step, a pH value adjustment step, and a palladium recovery step - Google Patents

Abstract

The present invention relates to a method for recycling palladium-containing wastes, which provides the recovery of precious palladium materials and includes: a pre-treatment step of grinding a palladium waste into powders; an aluminum recovery step of placing the palladium waste powders of the previous step into a hydrochloric acid impregnating agent, and using hydrogen peroxide as a catalyst, impregnating at 60-80 DEG C for at least 3 hours, then filtering to obtain a palladium and aluminum-containing impregnating solution and a filter residue; then adjusting the pH value of the palladium and aluminum-containing impregnating solution with ammonia water to obtain an aluminum precipitation product and a palladium-containing filtrate; and a palladium recovery step of heating the palladium-containing filtrate obtained in the previous step to 70 DEG C or below to evaporate the liquid, then cooling to obtain crystalline palladium.

Description

Palladium-containing waste recycling method

The invention relates to a metal waste recycling technology, especially the technical category of recycling metals containing palladium and aluminum.

According to the fact that palladium precious metal has extremely stable physical and chemical properties and beautiful color, it is often used as precious jewelry in human life, and is widely used in modern high-tech electronic technology because of its excellent and stable properties. Among them, the development of 3C (computer, communication and consumer electronics) products is the most dazzling, and the 3C industry is developing towards the demand trend of light, thin, short and high performance. Many electronic manufacturing processes have changed to surface mount components to suit fast Assembly and high-density circuit design. Of course, chip-type capacitors, resistors, and inductors are the three indispensable passive components in the 3C industry.

With the vigorous development of the domestic electronics industry, the waste derived from the manufacturing process of related electronic components is increasing. The 3C industrial waste is mixed with various types of mixed hardware such as integrated circuits, printed circuit boards, resistors and capacitors. Many of these are precious metals containing palladium. If these wastes are not properly recycled and treated, they will not only cause damage to the environment, but also an intangible waste from the perspective of the use and value of palladium precious metals.

Nissho "Nippon Mining & Metals Co., Ltd." published an invention patent No. 098114155 on "Separation Method of Rhodium and Platinum and/or Palladium" in 2010. The subject of this invention patent is to find a method that contains rhodium and Among the raw materials of platinum and/or palladium, rhodium is easily separated from platinum and/or palladium, and rhodium is recovered efficiently. The method for recovering rhodium of this invention is to chlorinate raw materials containing rhodium and at least platinum and/or palladium in a chlorine atmosphere to make platinum and/or palladium into soluble chlorides, and then to water the treated material After leaching to make platinum and/or palladium into a solution, it is separated by filtration, so that insoluble rhodium chloride remains in the residue; the residue is mixed with sodium chloride and burned in a chlorine atmosphere, thereby turning the rhodium into soluble sodium Salt, and then purify and recover it.

In 2011, Guo Ziwei, a graduate student at the National Taipei University of Technology,’s "Research on the Recovery of the Precious Metal Palladium from Wasted Activated Carbon Catalysts" revealed that waste catalysts were used as the object to separate and recover the precious metal-palladium, first using different acids , At different temperature, solid-liquid ratio, time, and the catalyst is first calcined at a high temperature to remove the carbon, and then pre-leached to obtain the most appropriate leaching conditions for palladium, and then use the leached palladium chloride solution as For the recovery object, formic acid is used as a reducing agent, and the optimum recovery conditions are obtained at different temperatures, pH, and ratio of formic acid to palladium chloride solution. Among them, the leaching rate is calcined in the catalyst at 800°C for two hours, at 90°C, the liquid-solid ratio is 20:1, and the reaction time is 2 hours, and the palladium leaching rate can reach more than 99% by leaching with aqua regia. The recovery process increases as the pH increases, and the reaction rate becomes faster. At 90°C and pH 8.31, when the volume ratio of formic acid to palladium ion-containing solution is 0.0067, the recovery rate can reach more than 99%, and the purity of palladium powder is 98.5 %the above.

In 2014, Huang Shengyuan, a graduate student of Yishou University,’s "Discussion on the Recovery of Palladium and Ruthenium by Ion Exchange and Electrolysis" revealed the use of ion exchange resin Dowex 1-x8 (Chloride form) and electrolysis to separate and recover the precious metal palladium dissolved in HCl. With ruthenium. Dowex 1-x8 is a strong base anion exchange resin, commonly used for the adsorption of precious metals. Using Dowex 1-x8 can effectively concentrate and adsorb palladium and ruthenium in HCl. Use 1% NH3 aqueous solution and 6 M HCl successively to separate the high The concentration of palladium is desorbed and separated from ruthenium. The electrolysis method uses graphite as the electrode to electrolyze the palladium and ruthenium dissolved in HCl, and study the optimal conditions for setting the electrolyte, current density, voltage, temperature, electrolysis time, and acid concentration to produce a better recovery rate .

Among the literatures on the aforementioned methods of recovering metal palladium, one uses too toxic chlorine gas, the other uses too corrosive aqua regia, and the other uses high-energy-consuming electrolysis, which is not friendly to the environment, nor In line with the modern trend of green energy and environmental protection, there is a real need to improve the current methods of recycling metal palladium.

Therefore, in view of the current problems in the recovery of palladium metal, the inventors worked hard to develop a method for recycling palladium-containing waste. Therefore, the purpose of the present invention is to provide a method for recycling palladium-containing waste with high economic value; Another object of the invention is to provide a palladium-containing waste recycling method with simplified recycling process and high safety.

To achieve the above objective, the present invention uses the following technical means:

Regarding a palladium-containing waste recycling method, it includes: a pre-treatment step, which is to grind the palladium waste into powder; a recycling step, which is to impregnate the palladium waste powder in the previous step into hydrochloric acid (HCl) And use hydrogen peroxide as a catalyst, soak at 60～80°C for at least 3 hours, filter to obtain a palladium, aluminum impregnating solution and a filter residue; then use the palladium and aluminum impregnation solution with ammonia After adjusting the pH value, an aluminum precipitation product and a palladium-containing filtrate are obtained; and a palladium recovery step is to heat the palladium-containing filtrate obtained in the previous step to below 70°C to evaporate the liquid, and then obtain it after cooling Crystalline palladium.

In the method for recycling palladium-containing waste, the powder in the pretreatment step is set to be less than 50 meshes (0.297 mm), but it is not limited to this fineness value.

In the method for recycling palladium-containing waste, the concentration of hydrochloric acid used in the aluminum recycling step is set to 10N-12N, but is not limited to this concentration.

In the method for recycling palladium-containing waste, the hydrochloric acid used in the aluminum recovery step accounts for 65-75% of the overall dosage, and the added hydrogen peroxide accounts for 25-35% of the overall dosage.

In the method for recycling palladium-containing waste, the impregnation solid-liquid ratio condition used in the aluminum recovery step is set to 1 g/70 ml to 2 g/70 ml, but it is not limited to this solid-liquid ratio condition value.

In the method for recycling palladium-containing waste, the pH adjustment and precipitation method in the aluminum recovery step is to adjust the acid-base value of the palladium-containing aluminum impregnation solution to pH 8 with ammonia water.

In the method for recycling palladium-containing waste, wherein the palladium and aluminum impregnation liquid system can leach at least 95.07% of palladium metal from the palladium-containing waste.

In the method for recycling palladium-containing waste, wherein the palladium and aluminum impregnation liquid system can dissolve at least 56.41% of aluminum metal from the palladium-containing waste.

The present invention uses the above technical means to achieve the following effects: 1. In recent years, my country's automobile industry and electronics industry have developed vigorously, and the demand for the rare precious metal "palladium" has greatly increased. Due to my country's lack of natural palladium metal resources, it must rely on foreign imports. Therefore, the palladium-containing waste recycling method of the present invention is extremely valuable. It can recover and purify the rare "palladium" metal in the "palladium-containing waste" and can be used in domestic and foreign markets. 2. The recycling method of palladium-containing wastes of the present invention is quite simplified, and the operating conditions of each step of the process are simple, which can reduce the recycling cost, and avoid the use of corrosive aqua regia to recover metals such as palladium and aluminum. High-risk chemical substances (such as chlorine gas, aqua regia) are used for processing, so the method of the present invention belongs to an environment-friendly green recycling technology, which conforms to the modern trend of green energy and environmental protection.

The present invention relates to a method A for recycling palladium-containing waste. As shown in Figures 1 and 2, it provides recycling of palladium-containing waste. The recycling technology of the present invention can achieve palladium and aluminum metal materials with a higher recovery rate. The recovery method of the invention includes: a pretreatment step a, an aluminum recovery step b, and a palladium recovery step c.

The pretreatment step a is to grind the palladium waste as shown into a powder. The fineness of the powder is preferably less than 50 meshes (0.297 mm), but the powder fineness is not limited to this value.

In the aluminum recovery step b, the palladium waste powder from the previous step is put into a hydrochloric acid HCl (preferably 10N) impregnant of any concentration, and hydrogen peroxide is used as a catalyst, and hydrochloric acid is used as a whole 65 to 75% (preferably 70%) of the dosage, and the added hydrogen peroxide accounts for 25 to 35% (preferably 30%) of the total dosage, and the immersion solid-to-liquid ratio condition is set to 1g/70ml, and at 60 Immerse at ~80°C (preferably 70°C) for at least 3 hours, and filter to obtain a palladium-containing, aluminum-containing impregnation solution and a filter residue. Usually at least 95.07% of palladium metal and at least 56.41 are dissolved from the palladium-containing waste. % Aluminum metal;

The palladium and aluminum impregnation solution is adjusted to its pH value (preferably pH 8) with ammonia (NH ₄ OH) to obtain an aluminum precipitation product and a palladium-containing filtrate.

The step c of recovering palladium is to heat the palladium-containing filtrate obtained in the previous step to 60°C to 80°C, preferably 70°C to evaporate the liquid, and obtain crystalline palladium after cooling.

Please refer to Figure 1 and Figure 2. The above-mentioned steps constitute the palladium-containing waste recycling method A of the present invention. The palladium-containing waste is first ground to facilitate a larger contact area with the immersion liquid. , Then use 10N～12N and the overall dose of 65-75% hydrochloric acid, and add 25-35% of the overall dose of hydrogen peroxide as a catalyst, and the best solid-to-liquid ratio conditions are set between 1g/70ml～2g/70ml, etc. Conditions, and then heat it to between 60°C and 80°C and immerse it for 3 hours. The palladium-containing waste can be leached out of at least 95.07% of palladium metal and at least 56.41% of aluminum metal in the pre-impregnation solution. The impregnating liquid containing palladium and aluminum and the filter residue are obtained.

After adjusting the palladium and aluminum impregnating solution to its preferred pH value of 8 with ammonia, an aluminum precipitation product and a palladium-containing filtrate are obtained. Finally, the resulting palladium-containing filtrate is heated to 60°C～80 Between °C, crystalline palladium is obtained after cooling, which can be used by the industry.

The present invention relates to a "palladium-containing waste recycling method", and the structure and manufacturing process of its various embodiments have not been seen in books or publicly used. It is in compliance with the requirements of a patent application. I sincerely ask the Jun Bureau to approve the patent as soon as possible. Prayer

For those who need to be clarified, the above are the specific embodiments of this case and the technical principles used. If the changes made in accordance with the concept of this case, the resulting functional effects still do not exceed the spirit covered by the specification and drawings, All should be combined with Chen Ming within the scope of this case.

A: Recovery method of palladium-containing waste a, b, c: steps

Figure 1: is a flow chart of the steps in the recycling method of palladium-containing waste according to the present invention. Figure 2: is a schematic flow diagram of specific and preferred operating conditions of the palladium-containing waste recycling method of the present invention.

A: Palladium-containing waste recycling method

a, b, c: steps

Claims (8)

A method for recycling palladium-containing waste includes: a pre-processing step, which is to grind the palladium waste into powder; a recycling step, which is to put the palladium waste powder from the previous step into a hydrochloric acid impregnant, and Hydrogen peroxide is used as a catalyst and immersed at 60～80°C for at least 3 hours, filtered to obtain a palladium, aluminum impregnating liquid and a filter residue; then the palladium and aluminum impregnating liquid is adjusted with ammonia water to adjust its pH value to obtain An aluminum precipitation product and a palladium-containing filtrate; a palladium recovery step is to heat the palladium-containing filtrate obtained in the previous step to between 60°C and 80°C to evaporate the liquid, and obtain crystalline palladium after cooling . The method for recycling palladium-containing waste according to claim 1, wherein the powder in the pretreatment step is set to be smaller than 50 meshes (0.297 mm). The method for recycling palladium-containing waste according to claim 1, wherein the concentration of hydrochloric acid used in the aluminum recycling step is set to 10N-12N. The method for recycling palladium-containing waste according to claim 1, wherein the hydrochloric acid used in the aluminum recovery step accounts for 65-75% of the total dosage, and the added hydrogen peroxide accounts for 25-35% of the total dosage. The method for recycling palladium-containing waste according to claim 1, wherein the impregnation solid-liquid ratio condition used in the aluminum recovery step is set to 1 g/70 ml to 2 g/70 ml. The method for recycling palladium-containing waste according to claim 1, wherein the pH adjustment precipitation method in the aluminum recovery step is to adjust the acid-base value of the palladium-containing aluminum impregnation solution to pH 8 with ammonia water. The method for recycling palladium-containing waste according to claim 1, wherein the palladium and aluminum impregnation liquid system can leach at least 95.07% of palladium metal from the palladium-containing waste. The method for recycling palladium-containing waste according to claim 1, wherein the palladium and aluminum impregnating liquid system can leach at least 56.41% of aluminum metal from the palladium-containing waste.

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