Recently, news came from the customer’s site that the production line of heavy calcium carbonate with an annual output of 500,000 tons built by Dawning macine was commissioned and operated normally and has been put into production. The client is a large local calcium carbonate milling company. A few years ago, it cooperated with Dawning macine and used several European Type mills. Customers own mines, mainly producing fine calcium carbonate, environmentally friendly putty powder, environmentally friendly water-based paint, activated calcium oxide, green building aggregates, etc.

Due to the increase in orders in 2021, in order to meet production needs and improve the company’s production specifications and standards, the user once again ordered 3 sets of Dawning macineMTW European Type mills to achieve the goal of increasing an annual output of 500,000 tons of heavy calcium powder, and gradually turn to carbonic acid. The cluster development of the calcium industry chain meets the needs of different industries for products, promotes the transformation and development of local enterprises, and realizes that equipment upgrades can drive efficiency upgrades!

The stones enters the jaw crusher,impact crusher for crushing through the feeder. After being classified by the vibrating screen, the various specifications of stones are obtained, so as to obtain the finished stones you need.

Equipment configuration: (silo)—-feeder—-jaw crusher—-impact crusher—-vibrating screen (finished stone)—-conveyor—- (can be made into finished stone).

The Dawn slag vertical mill is a kind of special equipment for grinding industrial waste such as  slag into powder. The mill is of simple and reliable operation with high drying ability.
Finished product fineness: 325-1250 mesh
Feeding size (mm): 50mm
Output capacity: 5-100t/h

For manufactured sand, it has become a kind of hot aggregates because it can even rival natural sand in terms of both physical properties (like partial, aggregates grading, compressive strength and powder content) and structure. More and more investors are care about it.

But it is a question how we choose sand making equipment. There are so many sand making machines in market, which one is what we need.

Actually, it is not difficult for users to choose one proper sand making machine, you can judge it whether it can comply with the standard listed below or not.

1. Whether The Sand Making Machine Can Meet Environmental Standards.

In the current situation of strict environmental protection, a good sand making machine will not pollute the surrounding environment. It will not produce too much dust and sewage. Generally, a high quality machine must be equipped three important parts: confined production space, high efficient dust removal and atomization spray device, ensuring to form a healthy ecosphere.

2. Whether The Sand Making Machine Can Shape Sand Or Not?

The main function of a sand making machine is to shape sand aggregates, which can ensure better finished products. If the sand maker can’t shape aggregates, it is basically the same as an ordinary crusher. A good sand maker combines the principles of “Rock to Rock” and “Rock to iron”, thus the material can be completely crushed and shaped in the chamber. It not only can make sand good partial, but avoid dust from overflowing as well.

Raymond mill is widely used in barite, calcite, potash feldspar, talc, marble, limestone, dolomite, fluorite, lime, activated clay, activated carbon, bentonite, kaolin, cement, phosphate rock, gypsum and more than 280 kinds of materials .

It is used in high-fine powder processing of materials in non-flammable and explosive mineral, chemical, construction and other industries with Mohs hardness not greater than 9.3 and humidity below 6%, such as glass and thermal insulation materials, and the particle size of the finished product is within the range of 80-325 mesh .

1. No Powder Or Less Powder Yield

Reasons:

• No air lock device is installed, causing the powder to be sucked backward.

• The air lock device is not tightly sealed, causing air leakage and large amount of air enter Raymond mill, causing the powder to be sucked backward. Air leaks at the soft connection between the analyzer and the pipeline.

• The shovel head is severely worn, causing the shovel blade to shovel too little material or the material cannot be shoveled up.

• Serious air leakage in the pipeline or pipeline flange joint.

• Pipeline installation is too long, too high, and too many elbows, increases the resistance of the pipeline.

Solutions:

• Install air lock device.

• Check the seal of air lock device.

• Reinstall and block the air leak.

• Check the wear condition of blade and replace it with a new one.

• Check carefully and block the air bleak immediately.

• Adjust and configure the piping device according to the general drawing.

2. The Final Powder Is Too Coarse Or Too Fine

Reasons:

The air volume is not appropriate, or the speed of the analyzer is not adjusted properly.

Solutions:

• Adjust the rotating speed of analyzer.

• The final powder is too coarse: if the adjustment of analyzer cannot achieve the expected effect, operators should turn down the valve of the air inlet pipe of the blower.

• The final powder is too fine: stop the analyzer or disassemble the analyzer.

• Increase the speed of the blower.

3. The Main Engine Stops Frequently, The Engine Temperature Rises, And The Blower Current Drops

Reasons:

• Feeding too much raw materials, a large amount of powder in the main engine block the air duct.

• The exhaust of the pipe is not smooth. The circulating air flow repeatedly rubs with the pipe wall and generates heat, so that the pipe wall is wet and the powder is adhered to the pipe wall, and finally the pipe is blocked.

Solutions:

• Clear the powders accumulated in the air duct and reduce the feeding volume.

• Make sure the moisture content of raw material is below 6%.

4. The Main Engine Has Loud Noise And Vibrates

Reasons:

• The feeding is uneven and the feeding volume is low.

• The upper and lower center lines of the main engine and the transmission device are not straight.

• The anchor bolts are loose.

• The thrust bearing is disengaged from the top and bottom during assembly.

• When installing, the thrust bearing is jacked up because there is no gap in the coupling.

• The hardness of raw material is too high.

• The raw material is too fine; there is direct friction between the grinding roller and the grinding ring with no material layer in the middle.

• The grinding roller is deformed and out of round.

Solutions:

• Adjust the feeding volume.

• Align the center.

• Fasten the anchor bolts.

• Check and readjust the thrust bearing.

• Adjust the coupling gap as required.

• Lower the rotating speed of spindle.

• Change the grinding roller.

5. The Blower Vibrates

Reasons:

• The anchor bolts are loose.

• Unbalance due to powder accumulation on the blades.

• The blades wear.

Solutions:

• Fasten the anchor bolts.

• Clear the powders accumulated on the blades.

• Change the worn blade with a new one.

6. The Transmission Device And Analyzer Heat Up

Reasons:

• The viscosity of lubricating oil is high, and the screw pump cannot be driven up, causing the upper bearing of the transmission device lack oil.

• The analyzer runs counterclockwise, the screw pump cannot pump the oil, and the upper bearing is short of oil.

Solutions:

• Check the grade and viscosity of the lubricating oil.

• Check the running direction of the analyzer.

7. Powders Enter The Grinding Roller Device

Reasons:

• Out of lubricating oil and accelerate the wear of bearings.

• Lack of maintenance and cleaning.

Solutions:

• Add the lubricating oil according to requirements.

• Clean the bearings regularly.