In the coal powder itself technical indicators fully comply with the requirements of the casting standards, if you can not detect the case of bright carbon sanzhuji suggests that the quality of coal powder can be judged by the characteristics of coke ballast.
1、coke ballast characteristics: 4-6 levels, according to the weight of the casting and wall thickness and process selection ze use level.
High-quality coal dust in the detection, look at the dry pot around the inner wall hanging metal luster, the more metal luster, the brighter, the better, while looking at the coke slag itself on the lower part of the metallic luster, showing the best silver-white metallic luster, and coke ballast has obvious expansion has a more uniform honeycomb, the height of 14-16mm, this coal dust is the best quality of natural coal dust, adding less, can fully meet the high quality castings on the demand for smoothness.sanzhuji combined with the use of sand casting equipment in the process of several coal powder, it is recommended to pay attention to the following points when purchasing.
1.1 coke ballast up to 4-6 level, coke ballast itself on the lower part of the metal luster less or no luster into gray, coke ballast expansion, with a more uniform honeycomb, this coal powder contains more impurities.
Coke ballast reaches 4-6 grade, coke ballast itself presents black gray upper and lower part without metallic luster, coke ballast without obvious expansion, this kind of coal powder is coking coal and gas coal with different coal structure, different specific gravity solubility, different water content, it is recommended to use mechanical pipeline pressed coal powder plant, when adding this kind of coal powder in winter because of the attention before and after the shutdown from the new pressure, coal powder may appear by cold, hot air, coal powder water absorption On the other hand, coking coal pulverized coal has different water content because of different specific gravity with gas coal pulverized coal, and coking coal pulverized coal will be deposited at the bottom of the storage solver for a long time after the increase of specific gravity by humidity, which will affect the normal use and cause damage to the equipment.
1.2 Coke ballast reaches 4-6 level, coke ballast shows gray-black, the upper lower part has a small or no metallic luster, coke slag around the obvious uneven black luster, dry pot wall has obvious uneven black oily luster, coke ballast obviously swells too high, there is obvious uneven size honeycomb, this coal powder is artificially synthesized.
2、coking coal and petroleum asphalt formulated and mixed with the processing of high-efficiency coal dust is also called synthetic coal dust, petroleum asphalt and coking coal formulated coal dust in processing, handling, unpacking, will produce a slight sexual skin allergies, fumes and odor when pouring smaller, this coal dust in adding to the molding sand when adding the amount is not easy to too much Noze will appear asphalt oil adhering to the casting surface is difficult to clean, add the right amount of finish is very good.
2.1 petroleum slag or coal pitch and coking coal formulated and processed coal dust in processing, handling, unpacking will produce heavy skin allergies and eye congestion and dizziness and other allergic phenomena, in the pouring of smoke and odor is larger and unpleasant, workers in a long time at the joint will appear dizziness, nausea and other phenomena, these two materials used improperly also dissolve easy to adhere to the casting surface is difficult to clean up.
2.2 petroleum asphalt, petroleum slag or coal asphalt and gas coal preparation and processing of coal dust, coke slag is black, obviously swollen, large honeycomb, dry pot wall has an obvious black oily luster, in the pouring will appear too much gas, (coal dust itself gas generation is higher than other coal dust) caused by the castings produce pores, join the improper asphalt more soluble easy to adhere to the surface of the casting is difficult to clean. Such as the use of petroleum slag or coal pitch and gas coal preparation and processing of coal dust, in the production, handling, unpacking will produce skin redness, eye congestion, dizziness, nausea, allergies and other phenomena such as heavy poisoning, in the pouring of fumes, the smell is unpleasant, workers appear dizzy, nausea and other phenomena.
Asphalt residue oil and coal pitch in foreign foundry industry towards the use of banned, the reason contains carcinogens such as aromatic polymers, in addition to coal dust sand released in large quantities endanger the common living environment of all mankind permanent highly toxic carcinogenic environmental hormone "dioxin".
3、 no coke slag characteristics or coke slag in the 2-3 level, gas coal pulverized coal, coke slag is black powder strong or slight coking, coke ballast itself shows a black, on the upper and lower are no metallic luster, dry pot wall has an obvious black metallic luster, this coal powder high water content in the casting process can consume a certain amount of heat, reduce the temperature of the molten iron. This coal powder burning point is very low, in the iron has not been completely filled with cavity, mixed in the sand most of the coal powder has been burned to exhaust, after burning the formation of dead ash (like paper soot) is dissolved in water, covering the surface of the sand and bentonite, resulting in a large number of fine powder "dead ash" in the sand in the sand to absorb the useful water in the sand, so that the sand in being Tight real-time resistance increases, the resulting "dead ash" so that the performance of the bentonite significantly reduced, resulting in a sharp increase in the mud content of the sand, permeability decreased significantly.
3.1 Gas coal characteristics: high bright carbon, high volatile content, low ash, low sulfur, high moisture content does not coke or poor coking.
3.2 Coal powder color and luster: coal powder from gray-black, brown to black, the higher the degree of coalification the darker the color, the better the coal quality, the more coal powder showing glass and diamond luster particles indicate that the better the quality of coal powder, coal purity, coal powder is gray-black, luster dark or no luster, the poor quality of this coal powder.
Qingdao Sanzhuji Equipment Manufacturing Co., Ltd. specializes in the production of sand reclamation equipment,foundry machines,Sand casting equipment,GS high efficiency rotary mixer,no-bake resin sand mixer,Jolt squeeze molding machine/Jolt-squeezing moulding machines,Multi- Piston Moulding Machine/Hydraulic multi-piston moulding machine,foundry molding machine,flaskless moulding machine,shot blasting machine,dust collector,according to the amount of old sand recovered Carry out plan customization, and provide sand reclamation equipment installation, commissioning, and training. Welcome guests to visit the factory.
