The gold content in the ore is extremely low. In order to extract gold, it is necessary to crush and grind the ore, and enrich it in advance or separate gold from the ore through mineral processing. Gravity separation and flotation are widely used in gold mineral processing. Gravity separation plays a very important role in placer gold production. Flotation is a widely used mineral processing method in rock gold mines. About 80% of rock gold mines in China use this method to select gold, and the level of mineral processing technology and equipment has been greatly improved.
For example, the circuit boards in some computer motherboards contain a small amount of gold, generally around 0.2g, and the gold content is mainly concentrated in cpu processors. Some small CPU processors contain as much as 0.5g of gold, and the whole motherboard can add up to 0.7g of gold. There are also some mobile phone circuit boards and memory chips, and some resistors and capacitors are also plated with gold. The highest gold content is the air conditioning chip.
Some are made of copper, which will darken and some will turn green if left for a long time, so gold will not change color. The colors are all gold and Huang Cancan. We should study hard and distinguish carefully to make money. At first, I suggested that you can recycle the circuit board, because there is gold in the circuit board, but only a small part. Because the gold content is small and mixed with various capacitors and resistors, there is little chance of counterfeiting and it will be safer to operate.
First of all, gold is a metal with corrosion resistance, no aging, good electrical performance, good stability and excellent ductility, so the use of gold can improve the service life of products and greatly reduce the failure rate of electronic products. Due to the high price of gold, manufacturers consider controlling costs. Although some people use copper, zinc and tin instead, they have to be used in integrated circuit boards, chip CPU, memory chips, heat sinks and other places, especially in some high-end electronic products. The higher the end, the greater the gold content.
The first step is calcination in a high-temperature furnace to remove the capacitance, resistance and some impurities;
The second step, some chemicals (aqua regia, etc. ) is used for decomposition.
Step 3, continue to heat and melt. The temperature should reach 1500 degrees. Because these circuit boards contain different metals, they need to be separated layer by layer. The density, volume and melting point of each metal are different and need to be separated layer by layer.
Baidu encyclopedia-gold beneficiation