Ways and methods of gypsum recycling are: the produce of construction gypsum powder, gypsum board and gypsum block; as cement retarder, production of cement and sulfuric acid and ammonium sulfate; can be made into paper filler; can be used as soil conditioner in agriculture field. Recently, an innovative of new technology is to extract rare earth elements from gypsum. Poland had reported this technology as early as in the 1990s about extracting rare earths from apatite; and our country carried out a experimental study of launched comprehensive utilization of gypsum and extraction of rare earths, it is learned that this innovative technology can solve three problems once: extracting important rare earth metals from industrial waste, gypsum building materials, and waste recycling. In phosphoric acid production process, part of the phosphate rock is not decomposed, gypsum washing the filtration process is not completely and the addition of additive are all reasons of gypsum containing phosphorus, fluorine and other impurities. gypsum can be used in pharmacy industry.

Kaolin is a kind of clay and clay rock mainly composed of kaolinite group clay minerals. Kaolin is white, fine and soft, with good plasticity, fire resistance and other physical and chemical properties. It is also an important non-metallic mineral, which is called the four major non-metallic minerals together with mica, quartz and calcium carbonate, and is widely used.

Kaolin is mainly used in paper making, ceramics and refractory materials, followed by coating, rubber filler, enamel glaze and white cement raw materials, and a small amount is used in plastics, grinding wheels, daily cosmetics, medicine, textiles, petroleum, chemical industry, building materials, national defense and other industrial sectors. With the rapid development of modern science and technology, some high-tech fields began to use a large amount of kaolin as a new material, as well as high temperature resistant porcelain parts of atomic reactors, space shuttles and spaceships, also made of kaolin.

The continued popularity of the kaolin sales market has led many regions with high-quality kaolin resources to encourage local enterprises to invest in the kaolin mining and processing industry. At present, all applications of kaolin must be grinded into fine powder before it can be added to other materials for complete fusion. At present, the equipment for processing the fine kaolin powder below 400 meshes are R Raymond mill, high pressure medium speed mill, overpressure V mill, etc., which can process the raw kaolin ore into 80-400 meshes of different specifications.

The complete configuration of the kaolin mill includes jaw crusher, bucket elevator, vibrating feeder, main machine of the mill, classifier, powder collector, pulse dedusting system, air compressor, electrical control system and the corresponding supporting grinding equipment of the mill. Collirick kaolin mill has a unique crushing chamber structure and advanced grading device to ensure that the equipment can achieve ultra-fine powder processing. Especially, it is suitable for processing products with high whiteness requirements, such as kaolin, calcite, calcium lime powder, etc., which are characterized by high whiteness, fine particle size, and no black slag.

Kaolin Processing Equipment

Due to the high industrial value of kaolin and the increasing demand for mining, Shanghai Collirick Machine has launched a full set of kaolin processing equipment, which is mainly composed of hammer crusher, bucket elevator, storage bin, vibrating feeder, Raymond mill, grader, magnetic separator, compressor, electric control system and some conveying equipment; It is applicable to the processing of superfine powder with materials ranging from 3.25 meshes to 3000 meshes.

For the back-flushing bag-type ultrafine vertical mill, after the bag room is cleaned, the pressure loss can only be reduced to 20-80% of that before cleaning because there is still a layer of adhering dust. when the cleaning is not complete, the adhesion layer is speckled. if the work is continued, the pressure loss will rise sharply. this shows that the pressure loss of the filter bag has decreased, which does not mean that the dust is completely cleaned.

For multi-chamber bag-type ultrafine vertical mills, the method of off-line cleaning by separate chambers is often used. at this time, although the actual total filtration area of ​​the ultrafine vertical mill is reduced, the pressure loss will increase slightly. when the cleaning is finished and the work is resumed, because the impedance of the bag chamber for cleaning has dropped and the air volume passing through it has increased, the total air volume of the reverse-blow bag ultrafine vertical mill will increase after cleaning, compared with before cleaning, and the pressure loss will increase. will drop.

The dust-removing effect of the back-flushing bag-type ultrafine vertical mill is relatively weak, so the filter cloth is generally recommended to use a lighter woven cloth [300-450g/㎡], which is rich in softness and has a small size change.

1. The grinding efficiency is high. The vertical roller mill of the SBM vertical roller mill adopts large-diameter double-row spherical roller bearings, which makes the equipment run faster, reduces the power consumption of startup, and the rotating device is also simplified. Delicate and able to meet customer needs.

2. The output can reach 615 tons per hour, and the phenomenon of calcium stone blocking the feeding port will not occur during the grinding process, which improves the grinding capacity and output of the equipment.

3. The output range of vertical roller mill is still very large, the output of small equipment is 0.65 tons per hour, and the output of large equipment is 615 tons. Equipment with different output not only differs in the amount of raw materials used, but also the structure design of large equipment is more complicated, so their prices There is definitely a big difference, and different manufacturers have different cost inputs and different pricing. We need to compare and choose equipment with high cost performance when purchasing.

Too much or too little bearing oil, oil pollution or oil quality is not in line with the lubricating system can ensure the normal operation of the ultrafine mill bearing, prevent foreign matter intrusion and sealing effect, but also eliminate friction heat, reduce friction and wear, and prevent the bearing from overheating Therefore, during production, be sure to ensure the amount and quality of ultrafine mill bearing grease. 

Solution: It is necessary to regularly add oil to the bearing box according to the requirements of equipment use to avoid too much or too little oil. If there is a problem with the oil quality, it is necessary to clean, replace the oil and seal in time. 

After long-term operation, some parts of the ultrafine mill may be severely worn or even broken. Common wear and tear parts include spring springs, bearings, pipe beams, beams and screen frames. The spring should be an important part of the ultrafine mill for shock absorption and noise reduction. 

If the spring is worn or broken, it will not only produce a large noise, but also cause disorder on the screen. Solution: The spring should be replaced in time to prevent production accidents.

First, pay attention to the pre-tightening degree of special screws under the condition that the screw is well lubricated and has no rubber damage.

The rubber is glued to the back of the gate. It is necessary to ensure that the rubber is firmly bonded and the surface is flat. Install the gate when it is fully dry. The special screws are designed according to the selection and structural dimensions.

After pre-tightening, the natural pre-tightening force between the gate and the U-shaped plate of the tank body should meet the design requirements, and no adjustment should be made unless there are special circumstances, otherwise the pre-tightening is too loose or excessive.

Tightening may lead to running water, and the lifting is not smooth. The above are the common mechanical failures of mechanical kaolin milling equipments. In actual production, attention should be paid to the maintenance and maintenance awareness of the kaolin milling equipment.

The kaolin milling equipment tank failure is mainly due to air leakage, which generally occurs in the equipment installation stage. Different degrees of water seepage and leakage may occur at the anchor position, and some may appear at the individual welds of the channel bottom channel.

Water seepage and leakage have no effect on the use of the equipment, but have a greater impact on the environment. Troubleshooting and troubleshooting: The surface connection of the tank body must ensure that the rubber is complete and free of deformation.

Fill the flange surface with sealant to seal, strengthen the seal, and pre-tighten the bolts after the joint surface is well connected. If it is found that the gap of the connected tank body leaks, first check whether the bolts are loose and whether the rubber is damaged. Try loosening the preload bolts, refill the sealant if the bolts and rubber or maintenance interval, and then preload the bolts.

Troubleshooting and troubleshooting: First of all, when the grinding mill is installed for the first time, the foreign objects in the tank should be removed first, and the large pulley should be turned to confirm whether it rotates flexibly and whether the belt is properly tight. 

Start the inspection to confirm that the belt is running in the correct direction (the correct direction is clockwise when looking down). Make sure that the belt is free of scratches, and then officially start. If the above problems occur during the operation of the grinding mill, the belt should be removed, and the stirring parts should be disconnected for separate investigation. 

The routine inspection part is the motor, the verticality of the motor shaft should be checked, the structure between the motor and the plate, the plate and the bracket is in good condition, the motor can be tested separately for wiring, and the small pulley can be visually checked to see if the operation is stable. 

Influenced by factors such as lubrication, if necessary, please ask professional motor maintenance personnel to carry out maintenance. 

When the feeding is stopped, grinding aids (such as dry coal and quicklime) can be added to the cylinder. After the grinding sound of the ultrafine vertical mill returns to normal, first feed a small amount of material, and then gradually increase the feeding amount until it is normal. 

Always observe whether the current of the main motor of the ultrafine vertical mill increases. If the current increases, it means that the "full grinding" phenomenon of the ultrafine vertical mill has been eliminated, and the feeding amount can be gradually increased. 

Stop the machine to check the compartment board and grate board. If the above methods do not work, the method of stopping and grinding can be adopted. Empty all the steel balls and materials in the barrel of the ultrafine vertical mill, and at the same time clean the attached materials on the liner and steel balls, then reload the balls and start the operation.

In the entire beneficiation process, the investment in grinding equipment can account for more than 50%. Therefore, care should be taken in the selection and operation process. When purchasing grinding equipment, many users will ask the manufacturer about the output of grinding equipment. 

Normally, the output of each vertical roller mill will be maintained within a certain range. If the output of the vertical roller mill suddenly drops, it is likely to be due to the problem of "full grinding", commonly known as "full grinding" or "boring grinding". Literally, "full grinding" means that there is too much material in the barrel of the grinding equipment in a short period of time, which cannot be removed in time, resulting in the loss of balance between the input and output. 

So how to judge whether the vertical roller mill is "full grinding"? What causes the "full grinding" problem of the vertical roller mill? And how do we solve the "full grinding" problem of the vertical roller mill? 

How to judge whether the vertical roller mill is "full grinding"? Just like a person will have symptoms before getting sick, there will also be some signs before the vertical roller mill appears "full grinding", so the operator is required to pay attention to the running state of the vertical roller mill at all times.