This product is widely used in drinking water, industrial water, sewage treatment and deep purification of wastewater; the use of gold activated carbon for gold refining, purification water and air purification. Its effective effect mainly depends on the rich pores of steam burning in the carbon body during the activation process. The specific surface area of ​​coconut shell activated carbon is generally more than 1500M2/g, which is 2 to 3 times that of bamboo charcoal and 10 to 20 times that of charcoal. Select activated carbon for the use of activated carbon.
The gold extraction series of activated carbon is made of high-quality coconut shell as raw material, which is refined by special activation process and post-treatment by air separation and particle cleaning. It has high strength, uniform particle size, developed microporous structure and selection of gold cyanide complex. Strong adsorption, easy to resolve, can be regenerated many times, repeated use. It has special adsorption properties for precious metals and is used for separation and extraction of precious metals. For example, in gold smelting, especially the carbon slurry method, the heap leaching method has excellent effects, and can also be used for water quality and air purification. It can also develop and produce special index activated carbon according to the actual requirements of users.
Illustration: Gold activated carbon
The dissolution rate of gold depends on the pH of the solution, and the optimum pH is 10.3. Gold can only be adsorbed by activated carbon after cyanidation. There are two methods for the adsorption of gold by activated carbon: one is heap leaching and the other is carbon slurry.
1. Heap leaching method:
Firstly, the ore is crushed to a certain particle size, and then stacked in a leaching device, and repeatedly washed with a certain degree of NaCN solution from top to bottom until the gold content in the eluent reaches a certain concentration. The gold-containing cyanide solution is successively passed through a set of adsorption columns packed with activated carbon. The cyanide complex is adsorbed on the large surface of the pores inside the char.
2. Carbon slurry method:
The gold-bearing ore is pulverized to a fineness of 300 mesh right and left. Add water to stir evenly to suspend the slurry. A solution of potassium cyanide (or sodium cyanide) is added to the slurry to form a water-soluble cyanide complex [Au(CN):]-. The slurry containing the cyanide gold complex is sufficiently contacted with the granular activated carbon under stirring in the adsorption tank in series. Most of the cyanide complex is adsorbed onto the inner surface of the activated carbon. The slurry tail containing only a small amount of cyanide compound is separated from the activated carbon and discharged.
There are two ways to recover gold from gold charcoal. One of the most primitive and uneconomical methods is to send gold charcoal to a smelter for roasting and high temperature smelting to obtain gold. The other method is more commonly used, that is, the gold cyanide complex on the gold charcoal is desorbed with a mixture of 0.1% to 1.0% of hot NaCN and NaOH, and then electrolyzed to obtain pure gold. The gold activated carbon has reduced activity after multiple adsorption and desorption, and must be regenerated.
Columnar activated carbon, powdered activated carbon, shell activated carbon use, coconut shell charcoal series and other six series, more than 50 varieties, shell activated carbon use, coconut shell activated carbon is made of high quality shell, coconut shell, walnut shell as raw material, after It is refined by activation, screening, pickling, high temperature activation, carbonization, sieving, drying and other processes. The product has the advantages of large specific surface area, developed void structure, high mechanical strength, strong adsorption capacity and easy regeneration. The activated carbon series products have distinctive features and outstanding advantages and are widely used in water plants, power plants, sugar factories, pharmaceutical factories, chemicals, oils and wineries, etc. at home and abroad. It can also be used for purification, refining, decolorization, catalysis, filtration and purification of gold smelting. Henan activated carbon manufacturer We are willing to provide you with the most sincere service with first-class service, first-class technology and first-class quality.
Coking wastewater treatment has always been a difficult problem. Activated carbon has always occupied a place in wastewater treatment. Gongyi City Xianke Water Supply Materials Co., Ltd. summarized three methods of activated carbon application in coking wastewater treatment.
Physical adsorption method:
The adsorption method treats wastewater by using a porous adsorbent to adsorb one or several solute in the wastewater to purify the wastewater. Commonly used adsorbents include activated carbon, sulfonated coal, slag, diatomaceous earth, fly ash, and the like. The method has high treatment cost and difficulty in regeneration of the adsorbent, and is not suitable for treating high-concentration wastewater, so it is often used for advanced treatment of wastewater. Bai Yuxing used coke-activated carbon two-stage adsorption method to deeply treat the effluent from the biochemical plant of a coking plant of Jinan Iron and Steel Co., Ltd. The results showed that the method had better removal effect on COD and suspended solids, and the removal rate of hardness and ammonia nitrogen was lower. . Using fly ash as adsorbent to treat coking wastewater deeply, the decolorization effect is good, and the removal rate of COD and volatile phenol is high. Shanxi Coking Plant cooperates with Shanxi Coal Chemical Institute of Chinese Academy of Sciences to study “coking ash treatment coking wastewaterâ€, which has been applied in coking plant.
PACT method:
Activated carbon powder is added to the activated sludge aeration tank, and the adsorption of organic matter and dissolved oxygen by the activated carbon powder is used to provide food for the growth of microorganisms, thereby accelerating the oxidative decomposition ability of the organic matter, and the activated carbon is regenerated by the wet air oxidation method. Studies have shown that the method has good removal effect and low investment and operating costs.
Biological fluidized bed:
The granular material such as sand, coke and activated carbon is used as the carrier, and the water flow flows from the bottom to the top, so that the carrier is in a fluidized state, and the biofilm is grown on the surface of the carrier, and the particle diameter of the carrier is generally 1.0 to 2.0 mm. The biological fluidized bed has the dual advantages of full mixed activated sludge method contact, and the biofilm method can withstand the double impact of load change shock, and has good treatment effect. Yang et al. used a fluidized bed anaerobic-anoxic-aerobic (A2/O) process to treat coking wastewater and conducted a pilot scale study. Under the condition of influent NH3-N concentration of 470mg/L, the effluent mass concentration is 10.33mg/L, the removal rate is >91.5%; the influent COD775～2986mg/L, the effluent mass concentration is 120～290mg/L. The removal rate is 66 to 93%.
Precautions:
1. During the transportation process, the activated carbon should be prevented from being mixed with hard materials. It is not allowed to step on or step on to prevent the carbon particles from breaking and affecting the quality.
2. Storage: It should be stored in porous adsorbent, so it should be absolutely prevented from water immersion during transportation, storage and use. After water immersion, a large amount of water is filled with active voids, making it useless.
3, to prevent tar substances in the use process, should prohibit the tar substances into the activated carbon bed, so as not to block the activated carbon gap, so that it loses its adsorption. It is best to have a decoking device to purify the gas.
4. Fire prevention: When storing or transporting activated carbon, it should prevent direct contact with fire source to prevent oxygen from entering and regenerate when the activated carbon is regenerated. After regeneration, it must be cooled to below 80 °C with steam cooling. Otherwise, the temperature is high and oxygen is encountered. The activated carbon is self-igniting.
Technical indicators:
Activated carbon is a kind of carbon product which has high-quality anthracite, charcoal or various kinds of husks as raw materials and processed through special processes by physical or chemical methods. It has a developed pore structure and specific surface area. It has a strong adsorption capacity, so it is widely used in industrial and civil fields such as air purification, anti-virus protection, water treatment, solvent decolorization.
Although activated carbon can have many varieties in terms of appearance and use, activated carbon has a common characteristic, that is, "adsorption". The reason why activated carbon produces adsorption is because it has a developed pore structure. Like the sponge we see, under the same weight conditions, the sponge can absorb more water than other objects, because it is developed. Pore ​​Structure. However, this pore structure of activated carbon is invisible to the naked eye because they are only between 1 x 10-12 mm and 10-5 mm, which is not much larger than a molecule. The degree of development of activated carbon pores is unimaginable. If 1 gram of activated carbon is taken, all the pore walls inside will be expanded into a plane, and the area will reach 1000 square meters (the specific surface area is 1000g/m2)! The main factor depends on the degree of development of the internal pore structure. In the production process, the only way to improve the adsorption performance of activated carbon is to control the production process, so as to increase the pore structure of activated carbon as much as possible within the unit volume. Therefore, the higher the adsorptivity of activated carbon, due to the large amount of pores, makes its own density become smaller and smaller, which is why the better the adsorption, the lighter the feel of activated carbon (provided that the same raw material is used, no dip Passing water or adsorbing other substances). At the same time, with the increase of adsorption, the production cost of activated carbon is higher, and it is increasing in geometric progression.
In order to unify the standard and control the production, in the activated carbon industry, the adsorption value of activated carbon is usually calibrated by iodine adsorption value or carbon tetrachloride adsorption value (CTC). The higher the adsorption value, the stronger the adsorption capacity of activated carbon.
The performance indicators of activated carbon products can be divided into physical performance indicators, chemical performance indicators, and adsorption performance indicators. Three performance indicators play a very important role in the selection and application of activated carbon.
Physical performance indicators include: shape, appearance, specific surface area, pore volume, specific gravity, mesh number, particle size, wear resistance, and floating rate.
Chemical performance indicators are: PH value, ash, moisture, ignition point, uncarbide, sulfide, chloride, cyanide, sulfate, acid soluble, alcohol soluble, iron content, zinc content, lead content, arsenic content, calcium Magnesium content, heavy metal content, phosphate, etc.
Adsorption performance indicators include: methylene blue adsorption value, iodine adsorption value, phenol adsorption value, carbon tetrachloride adsorption value, caramel adsorption value, quinine sulfate adsorption value, saturated sulfur capacity, sulfur penetration capacity, water capacity, chlorine Ethane vapor protection time, ABS value, etc.
The higher the adsorption value, the better the performance of the activated carbon. So how to easily identify the adsorption value of activated carbon without the detection equipment? Here are a few easy methods for reference.
1. Directly see the indicators provided by the manufacturer. The main adsorption indexes of activated carbon are: iodine adsorption value, carbon tetrachloride (CTC) adsorption value, methylene blue adsorption value, and iodine adsorption value to indicate the adsorption capacity of activated carbon for liquid substances. The adsorption value of carbon chloride is used to indicate the adsorption capacity of activated carbon for gaseous substances, and the adsorption value of methylene blue is used to indicate the decolorization ability of activated carbon. The higher the three indexes, the stronger the adsorption capacity of activated carbon. Therefore, when purchasing activated carbon, you can choose the activated carbon suitable for your own use according to your own use and the indicators provided by the manufacturer.
2, look at the volume: As already mentioned above, in order to improve the adsorption performance of activated carbon, only the pore structure can be made on activated carbon as much as possible. The more pores, the more loose the activated carbon, the lighter the relative density, so it is good. The activated carbon will be lighter in hand, and in the case of the same weight package, the activated carbon will be much larger than the inferior activated carbon.
3. Look at the bubbles. A small amount of activated carbon is put into the water. Due to the penetration of water, the water will gradually immerse into the pore structure of the activated carbon, forcing the air in the pores to be discharged, thereby generating a series of extremely fine bubbles, pulling out a small bubble line in the water. At the same time, it will make a sound of bubbles, which is very interesting. The more intense this phenomenon occurs, the longer the duration, the better the adsorption of activated carbon.
4, see the ability to decolorize. Another manifestation of the adsorption capacity of activated carbon is the ability to decolorize. Activated carbon has the ability to turn a colored liquid into a light color or a colorless one. This is actually because the activated carbon adsorbs the pigment molecules in the colored liquid. Because of this characteristic of activated carbon, it is widely used in the production process of brown sugar to white sugar in the sugar industry. Take two transparent cups, put pure water in one cup, and then drop a drop of red ink (you can use any kind of pigment that is easy to observe but does not change the nature of the water, such as blue ink, printer color ink, However, you cannot use ink and carbon ink. After mixing, pour half of the colored water into another cup for comparison. Put the activated carbon into the colored water, the amount should reach half or more of the water, so the effect will be more obvious. After standing for 10-20 minutes, it is compared with the comparative water sample. Under the same conditions, the stronger the decolorization effect is, the adsorption of activated carbon is indicated. The better.
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