How to judge the quality of expanded perlite and vitrified beads
Nowadays, due to the non-flammable advantages of closed-cell perlite in China, it is very popular in construction areas across the country. At the same time, the quality of perlite itself varies greatly, and local enterprises are also mixed with fish. Some enterprises are backward due to production equipment. In the future, the pursuit of high profits will lead to serious adulteration of raw materials, resulting in losses to the users. Therefore, here we will teach you some simple identification methods to identify the quality of closed-cell perlite vitrified microbeads, so as to avoid unnecessary losses. Square Pillow Case,Extra Large Pillow Cases,White Pillow Cases,Grey Pillow Cases SHAOXING KEQIAO DEQI GARMENT CO.,LTD , https://www.dqtextile.com
Expanded closed-cell perlite vitrified microbeads are a kind of acidic vitreous minerals. Due to the incombustibility of vitrified microbeads, they are used in large-scale construction in Sichuan and Chongqing in China. At the same time, because in the Inner Mongolia region of the production of perlite raw materials, the distance is far, the quality is not easy to buy, the locally produced vitrified beads can not meet the demand of various insulation materials manufacturers, resulting in rising market prices.
Normally, vitrified microbeads are closed-cell perlite, and open-celled pearlite is commonly known as expanded perlite. Production process of closed-cell perlite: During the heating process of perlite ore, it stays at a high temperature for a long time, and then heated to a high temperature of 1200 ° C or higher. The surface is vitrified to form a closed-cell environment. Therefore, the closed-cell perlite is also called vitrification. Microbeads. The closed-cell perlite has a large specific gravity, which is lower than 80kg/m3, generally above 110kg/m3, and the water absorption rate is small. The expanded perlite calcination temperature is above 800 °C, the surface is not melted, the specific gravity is much smaller than that of closed-cell perlite, and the water absorption is much larger.
The quality of vitrified beads is the vitrification rate. The key to the vitrification rate lies in the temperature and time. Only the electric furnace can reach the temperature and time. Today's petrochemical microbead manufacturers rarely use electric furnaces. Because electric furnaces have low output and high cost, most manufacturers use gas stoves for production. Coal mine gas stoves have low production costs, but they do not meet the national standards for vitrified microbeads. . According to the local standard of engineering construction in Sichuan Province DB51/T5061-2008 "Technical Regulations for Cement-based Composite Expanded Vitrified Beads Building Insulation System", the quality performance requirements of vitrified microbeads: • Tube strength ≥ 120kPa, • Volume water absorption ≤ 45 %. • Bulk density should be 80-130kg/m3. ——According to test data, construction experience and cost verification, the bulk density of expanded vitrified beads should be 110kg/m3 (both cylinder strength and volume water absorption can meet the requirements) That is 9.1m3 / ton, using it to prepare inorganic thermal insulation mortar can meet the requirements of the regulations, and the cost is better! This is also the consensus of the manufacturer of 11KG/bags for vitrified microbeads (ie 0.1m3, 11kg per bag, 1m3, 110kg for 10 bags)!
However, some unscrupulous manufacturers in the market have also said that they produce 11KG/bag of vitrified microbeads, but the volume of their bags is actually only 0.08~0.085m3 (10 bags are 0.8~0.85m3), although the price per ton It is slightly cheaper, but the price per cubic is 17% to 25% higher, and the mortar construction area is much less. These three have a long-lasting relationship! • Large bulk density, such as 130kg/m3, the volume is small (7.7m3/ton), the volumetric water absorption rate is small, the cylinder pressure is high, and it is not easy to crush when mixing and painting, but the theoretical construction area per ton is small, and it is prepared. The material cost is high, and the thermal conductivity of the vitrified microbead insulation mortar is not up to the requirement! • The bulk density is small, such as 80kg/m3, the volume is large (12.5m3/ton), and the theoretical construction area per ton is large. However, due to the small compressive strength of the vitrified microbeads, the volumetric water absorption rate is large, and it is easy to absorb water during mixing and application. , crushed, so the construction area is small, the quality of the mortar is poor. Perlite vitrified beads quality identification method:
one. Look at the floating rate of perlite vitrified beads: take a certain amount of vitrified beads to soak in the water, and take a few minutes to see how much the proportion of vitrified beads floating on the surface of the water, the more the bottom, the opening The more the perforated perlite absorbs water and naturally sinks to the bottom.
2. Look at the water absorption rate of perlite vitrification beads: the vitreous beads in the water are weighed out and weighed. The overweight part is the water absorbed by the vitrified beads. The higher the water absorption rate, the closed cell ratio. The lower the perlite, the higher the water absorption rate is used in the thermal insulation mortar, which may cause problems such as cracking and hollowing.
three. Look at the hardness and strength of the perlite vitrified microbeads: the open-cell expanded perlite is crushed by hand, and most of it will be broken after mechanical agitation by adding the rubber powder, and the vitrification of the vitrified bead surface is more than the perlite hardness. To be much larger, the rate of breakage after mixing is relatively low. However, it is not recommended to stir the vitrified beads for a long time in a blender.
4. Look at the pearlite vitrification beads: If a large amount of fine powder is found in the vitrified beads, it is usually processed from perlite ore (valley raw material) which has not been calcined at a sufficient temperature. The powder does not have a thermal insulation effect, and because the ore is not calcined, the specific gravity is large. Therefore, it is recommended to select vitrified beads with uniform particle size and less fine powder.
The above four points are simple methods for identifying perlite vitrified microbeads. I hope that everyone can buy real vitrified beads, not to be deceived by expanded perlite.