Feasibility Study on Recovering Gold from Waste Cyanide by Resin Pulp Method

I. Status of gold recovery from wastewater. There are about 200 cyanide gold extraction plants in China. Every day, a large amount of gold-containing wastewater is discharged in the form of pulp. By the current technology, only part of the gold can be recovered in a few mines. It is difficult to recycle due to the following reasons:
1. The tailings pond is seriously leaking, and there is no water in the reservoir.
2. Arid areas, no water in the library.
3. Other wastewater is remitted into the Taitai Mine, and the gold concentration is greatly reduced. There is no economic benefit in the recovery of gold.
4. The local climate is cold, the freezing period is long, and the device cannot be operated.
It is estimated that China's gold mines lose at least 100 kilograms of gold per year. It is a considerable asset!
2. Selection of new methods for recycling gold In order to recover this part of the gold, it can only be recovered in the tailings slurry of the cyanide plant. There are four ways to recover gold from the tailings slurry:
1. Carbon slurry method 2. Resin slurry method 3. Carbon powder flotation method 4. Filtration-adsorption method Among the four methods, the first two methods are economical, with low investment and low cost. Especially resin pulp method, due to resin It is more desirable to reduce the wear of small gold. It is worth noting that when the filtration-adsorption method is adopted, not only can gold be recovered, but also cyanide can be recovered, which is two-fold, but the investment is large and the cost is high. It is only used when cyanide treatment is considered. Filtration-adsorption method.
3. Characteristics of the resin slurry method We are developing the resin slurry method. It has the following advantages:
1. Not contaminated by organic matter.
2. The enrichment ratio is large and the gold grade is high.
3. Small wear and less loss of gold. Resin consumption is small. Resin grinding can be recycled, gold is not lost, and activated carbon is mostly powdery and cannot be recycled. According to the theoretical calculation, half of the recovery rate is not acceptable. Therefore, the actual income is much smaller than the theoretical calculation. It should not be used.
4. Desorption at room temperature, does not require a lot of power, desorption cost is low.
5. If you want to recover cyanide while recovering gold, you can do it.
6. Fast adsorption speed, saving adsorption time and saving electricity.
The disadvantage is that the resin particle size is much smaller than that of activated carbon, which is easy to block the screen; the use of thiocyanate during desorption causes an increase in drainage reducing compounds and an increase in the consumption of sewage treatment. In addition, the price of ion exchange resin is higher than that of activated carbon. Much more.
IV. Economic Benefits Estimation of Resin Pulp Method Technical Data:
CIP cyanide plant scale: 100t/d cyanide tail gold concentration: 0.05g/m 3 tail liquid volume: 130m 3 /d
Secondary adsorption time: 2h resin concentration: 2% adsorption rate: 80%
1. Annual adsorption gold amount: 130m 3 *0.05g/m 3 *80%*300d/a=1560g/a
2. Annual output value: 1560g/a*96.46 yuan/g=150,000 yuan/year 3. Annual cost: 8kw*0.5 yuan/kw*300d/a+12 months*350 yuan/month. People*2 people+10000 yuan Desorption fee +300d/a*0.03kg/t*100t/d*25 yuan/kg=42100 yuan/year 4. Annual profit: 15-4.21=10.79 million/year
investment amount:
1. Adsorption tank: 2 sets of original sewage treatment tanks are modified. Replace with double impeller low-speed stirring device. Investment 25,000 2. String resin device: 2 sets *2000 yuan / set = 0.4 million yuan 3. Resin removal device: 0,5 million yuan 4. Desorption electrolysis device: 40,000 yuan 5. Resin: 600kg * 35 = 21,000 yuan Total investment: 95,000 yuan investment return period: 12 months five. Haigou gold mine cyan tail recovery gold simulation production capacity : 300t/d tail liquid production: 450m 3 /d tail liquid gold concentration: 0.05g/m 3
Gold recovery rate: 80% Resin usage: 1.6 tons Annual recovery gold: 4500g/a
Annual income: 520,000 yuan Annual cost: 150,000 yuan Annual profit: 370,000 yuan Investment: 125,000 yuan Return to the current period: 4 months 6. Equipment list 1. Reducer (with 30m3 mixing tank) 2 sets 2*0.5 million Yuan 2. Double impeller mixing paddle 2 sets 2*0.3 million 3. In addition to wood chip sieve 2 sets 2*0.1
4. String resin pump 2 sets 2*0.2
5. Separate resin screen 2 sets 2*0.05
6. Saturated resin cleaning equipment 0.2 million 7. Desorption electrolysis equipment 1 set 4.0 million 8. Resin D301 1.6 tons 56,000 9. Distribution 0.2 million 10. Civil construction fee 0.2 million 11. Subtotal 125,000 yuan, desorption electrolysis The device includes:
1.100kg/batch desorption column. One diameter 1000mm high 1500mm PVC plate manufacturing. 0.4 million 2.200L/h electrolyzer one. 16,000.
3.350A rectifier one. 0.8 million.
4.1000L solution tank one set. 0.4 million.
5.0.2-1M 3 magnetic drive pump one. 0.4 million.
6. One regenerative equipment. 0.4 million.
7. Subtotal: 4.0 million.
7. Promotion prospects The success of the project can be extended to at least 40 cyanide plants nationwide. We can get at least 1 million yuan in technical service fees. We can recover 80 kilograms of gold per year for the country. The output value is 8 million yuan and the profit is 6 million. yuan.
VIII. Gold Silver Square RIP process total cost (1991)
Item Consumption Material Name Quantity Unit Price Amount Remarks 1 Sodium cyanide 2.89 16 46.24 The quantity is kg/mine,
2 lime 11.6 0.4 4.64 units are yuan / kg,
3 steel ball 4.5 5.5 24.75 The amount is yuan / t mine.
4 electricity 70 0.5 35.0
5 Labor 15
6 thiourea 0.37 13.0 8.14
7 sulfuric acid 0.42 0.6 0.25
8 sodium hydroxide 0.2 2.5 0.5
9 bleaching powder 7.58 1.5 11.37
10 Management fee 5.0
11 Depreciation 15
12 subtotal 162.56

Attached equipment:
7-stage leaching ∮3×3.4 tank 4kw motor 6-stage adsorption ∮2.2×2.5 2.2kw
3 sections of sewage treatment ∮3×3.4 4kw
6 desorption columns ∮ 0.4×4
3 diaphragm electrolyzers 0.86x0.76x0.75
Estimated data:
Ball mill electromechanical consumption: 22kwx2 sets of classifiers: 10kw
Sand pump : 20kw
Broken : 10kw
Total : 147.2kw
I. Significance, research content and technological advancement of the project There are more than 150 gold cyanide plants in China. It is estimated that 300,000 cubic meters of cyanide tail liquid will be discharged every year, and the gold concentration of tail liquid will be 0.05-0.1g/M3. Gold 150-300kg. The technology for recovering gold from the tailings pond wastewater invented by our company can only be used in 30-40 cyanide plants. Other tailings ponds or a large amount of other wastewater remittance or tail liquid leakage or All evaporated, not recycled.
The dissolved gold in the tailings of such cyanide plants is preferably recovered in the plant and before being discharged into the tailings pond. There are two processes of CIP and RIP. Due to the carbon adsorption speed of the carbon in the CIP process Slow and wear-intensive, charcoal needs to be regenerated, so we chose the RIP process. The process has the following advantages:
1. Not only can recover gold, but also can not recover silver, copper and cyanide, the benefits are better and have environmental benefits.
2. Resin desorption does not require heating, and the cost is low.
3. The resin adsorbs gold at a fast rate, and the adsorption time can reach more than 90% in 2-3 hours. The existing wastewater treatment facility can be used as an adsorption tank to save investment and site.
4. The resin is spherical and wear-resistant. Compared with carbon, it reduces the loss of gold and improves economic benefits.
5. We are investigating the use of new adsorption resins to make desorption easier and less costly.
3. We have been studying the resin method for nearly 8 years. We have completed the ion exchange method to recover cyanide and ion exchange method to recover gold from the tailings reservoir overflow water. We have designed a complete set of equipment and accumulated a wealth of equipment. Experience. At present, the test work for recovering gold from the cyan tail of Minjiang Gold Mine has begun. According to our small test results, we chose the domestic resin D301 which is similar to the performance of the former Soviet AM-6B and plans to choose new ones. The cyanide test is carried out when the performance of the resin is better.
4. Main technical and economic indicators 1. Resin density: 1% 2. Adsorption time: 3 hours 3. Recovery rate of gold and silver, etc.: >85% 4. Cost: ?<20 yuan/gram of gold 5. Investment: 100t/d Cyanide plant: 150,000 yuan 6. Return to the current period: 0.5-1.5 years V. The technical route, technical key and test method adopted by the project temporarily use thiocyanate to elute gold, silver and copper, and acidify to recover cyanide. When the adsorption resin is selected, a simpler desorption regeneration method is adopted.
The key to technology is how to reduce production costs and investment.
The process flow of the test is as follows:
Estimated funding materials 1. Test funding: 100,000 yuan
2. Investment: 100t/d cyanide plant scale: 150,000 yuan

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