product details
Electroplating sludge is the final product of wastewater treatment in the electroplating industry, which contains a large amount of precious metals such as copper, nickel, chromium, iron, and zinc. Electroplating sludge mainly comes from solid waste generated by liquid-phase chemical treatment of various electroplating waste liquids and electrolytic tank solutions in industrial electroplating plants. Due to the different production and treatment processes of various electroplating manufacturers, the chemical composition of electroplating sludge is quite complex, mainly containing heavy metal compounds such as chromium, iron, nickel, copper, zinc, and soluble salts.
During the initial treatment of electroplating sludge, electroplating enterprises need to convert various heavy metal salts in the electroplating waste liquid into corresponding hydroxides and precipitate and solidify them. Therefore, most electroplating manufacturers add relevant reducing agents, neutralizing agents, flocculants and other chemicals when treating electroplating waste liquid, resulting in an increase in chemical components in the electroplating sludge, and various heavy metal compounds are dispersed in the components with low content. Especially for some electroplating enterprises that use lime or calcium carbide as neutralizing agents, a large amount of gypsum or calcium hydroxide is produced through chemical reactions during neutralization treatment, which increases the total amount of electroplating sludge and reduces the content of heavy metal components, making further harmless treatment, separation, and comprehensive utilization more difficult. According to our field investigation, the moisture content of newly treated electroplating sludge is generally high, reaching 75% to 80%. The compound content of chromium, iron, nickel, copper, and zinc is generally around 0.5% to 3% (calculated as oxides), gypsum (calcium sulfate) content is 8% to 10%, and the content of other water-soluble salts and impurities is around 5%.

Product details of electroplating sludge dryer:

Overview of Electroplating Sludge Drying Machine:
Wedge shaped hollow blades are densely arranged on the hollow shaft, and the heat medium flows through the blades through the hollow shaft. The heat transfer area within a unit effective volume is large, and the temperature of the heat medium ranges from -40 ℃ to 320 ℃. It can be steam or liquid, such as hot water, thermal oil, etc. Indirect conduction heating does not carry away heat with air, and the heat is used to heat the material. The heat loss is only the heat dissipation to the environment through the insulation layer of the device body. The wedge-shaped blade heat transfer surface has self-cleaning function. The relative motion between the material particles and the wedge-shaped surface produces a scrubbing effect, which can wash away the attached material on the wedge-shaped surface and maintain a clean heat transfer surface during operation. The shell of the blade dryer is W-shaped, and generally two to four hollow mixing shafts are arranged inside the shell. The shell has sealed end caps and upper caps to prevent material dust leakage and collect material solvent vapor. Set up a stopper at the discharge port to ensure the height of the material level, so that the heat transfer surface is covered by the material and fully functional. The heat medium flows through the shell jacket and hollow stirring shaft through the rotary joint. The hollow stirring shaft has different internal structures according to the type of heat medium to ensure the best heat transfer effect.

Application of electroplating sludge dryer:
The blade dryer has been successfully used in the fields of chemical, petrochemical, dye, industrial sludge drying, paper mill sludge drying, printing and dyeing sludge drying, and domestic sludge drying. The characteristics of heat transfer, cooling, and stirring of the equipment enable it to perform the following unit operations: calcination (low temperature), cooling, drying (solvent recovery), heating (melting), reaction, and sterilization.

The stirring blade is also a heat transfer surface, which increases the heat transfer area per unit effective volume and shortens the processing time. The wedge-shaped blade heat transfer surface also has self-cleaning function. The compression expansion mixing function ensures uniform mixing of materials. The material moves in a 'piston flow' along the axial direction, and within the axial range, the temperature, humidity, and mixing gradient of the material are very small.
Using thermal oil as the heat medium, the blade dryer can complete low-temperature calcination work. For example, calcium sulfate dihydrate (Ca2SO4 · 2H2O) is calcined and converted into calcium sulfate hemihydrate (Ca2SO4 · 1/2H2O). Sodium bicarbonate (NaHCO3) is converted into pure alkali (Na2CO3) through calcination.
Cooling media such as water, cooling salt water, etc. can be used for cooling. For example, the blade type cooling alkali machine used in the soda ash industry replaces the old-fashioned air-cooled cooling alkali machine, saving energy and exhaust gas treatment equipment, reducing operating costs, and can also be used for cooling titanium dioxide, nickel iron alloy powder, and various granular materials. The material can be cooled from 1000 ℃ to less than 40 ℃ in a single machine.
Drying, the main function of the equipment, does not use hot air, making solvent recovery, energy consumption, and environmental control in an ideal state that is easy to handle. It is particularly suitable for solvents that need to be recycled, flammable and easily oxidizable heat sensitive materials. It has been widely used in the fine chemical, petrochemical, and dye industries.
The uniformity of temperature, humidity, and mixing degree within the axial range allows the equipment to be used for heating or melting, or for some solid material reactions. It has been successfully used in the compound fertilizer and modified starch industries. Paddle dryers can be used to sterilize food and flour. The large heating area within the effective volume of the unit quickly heats the material to the sterilization temperature, avoiding prolonged heating and changing the quality of the material.
Electroplating sludge dryer is suitable for materials:
Petrochemical industry: polyolefin powder, polycarbonate resin, high and low density polyethylene, linear low density polyethylene, polyacetal particles, nylon 6, nylon 66, nylon 12, acetate fiber, polyphenylene sulfide, propylene based resin, engineering plastics, polyvinyl chloride, polyvinyl alcohol, styrene, polypropylene, polyester, formaldehyde, styrene acrylonitrile copolymer, ethylene propylene copolymer.
Environmental protection industry: PTA sludge, electroplating wastewater sludge, boiler ash, pharmaceutical factory waste, sugar factory waste, monosodium glutamate factory waste, coal ash.
Feed industry: soy sauce residue, bone based feed, distiller's grains, food scraps, apple pomace, orange peel, soybean meal, chicken bone feed, fish meal, feed additives, biological sludge. Food industry: starch, cocoa beans, corn kernels, salt, modified starch, pharmaceuticals. Chemical industry: Soda ash, nitrogen phosphorus potassium compound fertilizer, kaolin, bentonite, white carbon black, carbon black, phosphogypsum, sodium fluoride oxide, calcium nitrate, magnesium carbonate, sodium cyanide, aluminum hydroxide, barium sulfate, calcium sulfate, calcium carbonate, dyes, molecular sieves, saponins.
Characteristics of electroplating sludge dryer:
The blade dryer has low energy consumption: due to indirect heating, it does not carry a large amount of air to take away heat. The outer wall of the dryer is also equipped with an insulation layer. For slurry materials, evaporating 1kg of water only requires 1.22kg of steam.
The blade dryer system has low cost: it has a huge heat transfer surface per unit effective volume, which shortens processing time and reduces equipment size. This greatly reduces the building area and space.
Wide range of material processing: Using different heat media, it can handle both thermosensitive materials and materials that require high-temperature treatment. Common media include steam, thermal oil, hot water, cooling water, etc. It can operate continuously or intermittently and can be applied in many fields.
Low environmental pollution: No use of portable air, minimal dust and material entrainment. The solvent evaporation of the material is very small, making it easy to handle. For materials that are contaminated or require solvent recovery, closed-loop circulation can be used.
Low operating costs: The device operates normally with only 1-2 people per day. Low speed stirring and reasonable structure. The wear and tear is small, and the maintenance cost is very low.
Stable operation: Due to the special compression expansion stirring effect of the wedge-shaped blade, the material particles are fully in contact with the heat transfer surface. In the axial range, the temperature, humidity, and mixing gradient of the material are very small, thereby ensuring the stability of the process.