stevia

Expanded Polystyrene EPS is a white object from Expandable Polystyrene Beads containing a volatile liquid blowing agent is heated after forming an advance in the mold. It structural characteristics of fine obturator. XPS is use Expanded Polystyrene Resin as a raw material, through a special process of continuous extrusion foaming of rigid plates, internal independent closed cell structure, is a high-compression, non-absorbent, moisture-proof, airtight, lightweight, corrosion-resistant, long life, low thermal conductivity, excellent performance of environmentally friendly insulation material.
Excellent, long-lasting insulation properties:
XPS thermal conductivity is 0.028 w/mk, having high thermal resistance, low linear expansion characteristics. Its thermal conductivity is much lower than other insulation materials, such as: EPS board, Foam Polyurethane, Insulation Mortar, Cement Perlite. And because the material has a stable chemical and physical structure, thermal insulation properties of this material ensures durability and stability.
Superior resistance to water, moisture resistance:
XPS resistance to water, moisture is better than other insulation materials, XPS board has a compact closed-cell structure. Expanded Polystyrene molecular structure itself does not absorb water, positive and negative plates are no gaps. Therefore, low water absorption, excellent moisture and anti-permeability.
Corrosion, durability:
The general aging of rigid foam insulation material is easy to produce a few years later, subsequently lead to water absorption, resulting in performance degradation. And because XPS board has excellent anti-corrosion, anti-aging and insulation properties, at high water vapor pressure, can still maintain quality, make the useful life of 30 to 40 years.
Nature of EPS and XPS (Brittle)
Expanded Polystyrene Board due to the large area when pasting, the possibility of external walls cracking high level, especially in the paint surface. Usually by increasing the flexibility of cracking mortar to resist cracks that may arise. On the material itself, flexibility of XPS is much superior than EPS.
According to the above comparison, as wall insulation, the overall performance is better than EPS and powder particles of polystyrene insulation slurry, but the price is higher.

Nontoxic Polyvinyl Alcohol has biodegradable excellent performance, fully in line with modern society demands for environmentally friendly products, with good prospects for development. China is the largest country in the world PVA production capacity, production, consumption. Polyvinyl Alcohol domestic product differentiation rate is not high, the conventional product oversupply, while the larger part of the market demand for high value-added products have to be imported, for the future development of the domestic high-end products refined PVA has broad prospects.
Polyvinyl Alcohol production equipment and process complexity scale determines the stability of supply. Due to the long production process of Polyvinyl Alcohol, the number of devices and more complex production process, investment, technology and management is not easy to grasp, general corporate and investor difficult to produce.
Therefore, the state has not had a new factory building, just on the basis of the original device to transform the old supply -scale expansion of stability, to avoid disorderly competition in the market for the normal operation of the production provides favorable conditions.
Due to the rapid growth in consumption China Polyvinyl Alcohol, prices continued to rise, coupled with the rapid development in recent years, the domestic coal chemical industry, formed a gasification to methanol, methanol to acetic acid, acetic acid, calcium carbide acetylene and ethylene acetate, vinyl reproduction of Polyvinyl Alcohol product chain, making many coal chemical companies have development plans Polyvinyl Alcohol.
Growth in domestic GDP, increased textile exports, the rapid development of the construction industry, particularly the major downstream products remain relatively stable PVA fiber production growth, price volatility is not, for the formation of strong support polyvinyl alcohol industry.
There are usually two ways to produce Polyvinyl Alcohol. One is use ethylene as raw material, the preparation of Vinyl Acetate, and then prepared Polyvinyl Alcohol. The other is use Acetylene (divided into Calcium Carbide and Acetylene gas) for the preparation of raw material Vinyl Acetate, and then prepared Polyvinyl Alcohol. In Japan, the United States and other countries, usually produce Polyvinyl Alcohol used the ethylene as raw materials, namely oil and ethylene method. China has the most complete methods of production of raw materials of PVA.

Tungsten is 1781 by the Swedish chemist Scheele discovered. By the early 1900s, due to its development of a range of applications, such as Tungsten was first exhibited in 1900 as an alloying element in the production of high-speed steel and Tungsten bulbs using the World Exposition in Paris; 1927-1928 developed into a Tungsten -based sintered hard quality alloys, Tungsten metallurgy industry began to produce and develop.
Tungsten products in order to meet the increasing user demand for quality, lower costs, reduce pollution of the environment, Tungsten metallurgy technology has made great progress, new advanced technology completely replace traditional techniques. Mainly in the following areas:
Tungsten mineral raw materials decompose, the early industrialization of the Soviet suppression of cooking to become not only efficient handling of scheelite, in low-grade scheelite ore, while capable of handling mixed black and white Tungsten ore; Based on the theoretical study was a breakthrough on NaOH ( sodium hydroxide ) decomposition by only handle low calcium wolframite developed into treatments include scheelite, refractory Tungsten ore mineral raw materials, including a variety of general-purpose technologies. Of course, with the phasing out of the NaOH melt legitimate, low efficiency sintering soda, hydrochloric acid decomposition method, serious environmental pollution traditional methods. While also reducing the requirements for beneficiation , greatly improved resource utilization.
In terms of pure Tungsten compound preparation, crude Na2WO4 solution strongly basic anion exchange purification and transformation processes, and short process, low cost , and high quality products in a wide range of magnesium to replace the classic purification - traditional chemical transformation processes. With corresponding quaternary want extraction and purification of transition from laboratory research began to move toward industrialization, presents a welcome prospect. In addition to the selective precipitation of molybdenum, tin, antimony, arsenic and other high technology research and development success Impurity from Tungstate solution and widely used, greatly improve the purity Tungsten and Tungsten products for metallurgical process materials adaptability.
In terms of the metal Tungsten powder preparation, in the 1970s, advanced hydrogen reduction of Tungsten blue replaced the yellow Tungsten hydrogen reduction process, to the 20th century, purple Tungsten hydrogen reduction method further replaced by hydrogen reduction of Tungsten blue, so that production the physical properties of Tungsten powder of control to achieve a more advanced level, to further improve the overall quality of Tungsten powder.
At the same time, a variety of processing Tungsten metallurgy technology successfully developed secondary resources, make use of Tungsten secondary resources both in the technical level or on the utilization of the recovery are greatly improved.
Science and technology are primary productive forces, Tungsten resources as an important strategic material is an important resource of the world, must be reasonable utilization cycle.

Silicone Rubber:
Silicone Rubber noise prevention earplug: Wear comfortable, noise prevention and eardrum protection.
Silicone Rubber fetal head suction device: easy to operate, safety for use. It can transform according to the size of the fetal head, and will not pick up the fetal scalp. It can avoid the ills of the scalp hematoma and intracranial injury, which largely reduce the pain of giving birth pregnant women.
Silicone Rubber artificial blood vessel: It has a special physiological function with no reject from Human body. After a while, it can integrate with human body closely.
Silicone Rubber tympanic membrane patches: The membrane is thin and soft .it has good smooth and tenacity.
In addition, Silicone Rubber is also a good material for artificial trachea, artificial lung, artificial bone and silicon rubber duodenal tube.
Silicone Oil:
The application of Silicone Oil used as release agent:
Since the product with rubber, plastic, metal and other non-stick, and also can be used in a variety of rubber, plastics molding release agent and for precision casting. It is not only convenient to use mold release agent to do, and make the product surface clean, smooth, clear texture.
The application of Silicone Rubber used as defoamers:
Since the surface tension of the product is small, an does not dissolve in water, animal and vagetable oils and high boiling mineral oil, has good chemical stability and is non-toxic. The application of Silicone Rubber used as defoamers have been widely used in petroleum, chemical, medical, pharmaceutical, food processing, textile, printing and dyeing, paper and other industries, only need to add about 10 to 100 PPM Silicone Oil and it will have good antifoaming effect.
The applicatio of Silicone Rubber used as insulation, dust and mold coating:
1. The isolation device used in the process, can improve the insulation performance of the device.
2. The optical instruments used in the process, can prevent the lens, a prism mold.
3. Deal with the bottle, can extend the shelf life of drugs, does not make preparations due to the loss of sticky wall. The film with the film surface treatment may be a lubricant to reduce friction and prolong the life of the movie.

Our sea rich in water resources, using seawater as industrial water for the growing lack of freshwater conservation has important strategic significance. However, the corrosive effects of sea water due to strong metal to make the water in the industrial application is limited. Copper for its excellent strength, machinability, electrical conductivity and thermal conductivity, especially excellent corrosion resistance, making copper equipment, piping, etc. at the beginning instead of the steel used in more areas in the marine environment. Typically, the copper corrosion tendency is small, but high conductivity salt in the medium, the surface of the metal easy to form the micro and macro cells, the more severe the copper corrosion occurs. Thus copper corrosion and protection issues have received increasing attention, add a simple and effective way to solve this problem inhibitor in corrosive media. Many types of copper corrosion inhibitor, which is a kind of organic matter is very important and the most widely used inhibitor. Copper metal corrosion inhibitor compounds from the 1920s began using arsenic compounds as copper corrosion inhibitor research began in the 1930s, but in recent years more and more aspects of research shifted to organic corrosion inhibitors.
The early 1950s, Benzotriazole (BTA) has become one of the most effective and commonly used corrosion inhibitor of copper and its alloys.
BTA has superior anti-chlorine properties, N atom lone pair electrons in the molecule ligand bond connected with Cu, alternating with each other to form a chain-like polymer film. M.Statake study reported the molecular structure of the surface film formed on the copper BTA TOF spectra (Tofsims), BTA inhibition effect is due to the near neutral solution in the copper surface to form a Cu (I) -BTA polymer composite film. For Cl- of Cu corrosion, Hung Chuan using linear potential sweep and Tafel experiments further study BTA inhibition mechanism at high concentrations of copper chloride environment. When the BTA mass fraction greater than 0.112%, BTA cover layer has effectively masks the most active copper surface area, or cover layer thickness limit is reached, so that the corrosion potential Ecorr stabilized. Although BTA good inhibition effect, but there is a certain toxicity, higher prices, when use is restricted. Found, BTA derivatives have excellent copper corrosion performance, but the hydrogen-triazole ring is substituted with a methyl group, is not conducive to the stability of the molecule at the surface of the copper protective film is formed, the inhibition effect will be greatly reduced, and After the introduction of alkyl benzene ring in the inhibition effect can be enhanced. TTA, BTA molecular structure than one more non-polar group, a hydrophobic monomolecular layer which is formed a better film, and the presence of methyl groups on the reaction between the molecules and the Cu did not interfere. Therefore, the inhibition performance is better than TTA, BTA, its corrosion behavior is more durable, and better use of effects mixed with BTA. However, the amount of TTA problem there is a limit to study the corrosion inhibition TTA in 3% NaCl solution for copper Yang Mai's, who used light voltage method. The study found that there is a critical concentration phenomenon in the reaction, the TTA was added at less than the critical concentration, the formation of a dense film having no voids, the void region is susceptible to corrosion of the anode, a cathode to form large and small anode! type internal battery, causing localized corrosion of copper matrix; while above this critical concentration increases with the concentration of TTA, TTA protective film becomes more dense, the greater the thickness of the copper Cl- prevent erosion, corrosion inhibition and the more good.

Vanadium solid wastes contain many important economic value of the metal, should be positive to recycling, waste, the harm to benefit, so as to create considerable economic benefits and social benefits.
1. Recovery of Vanadium from the waste Vanadium catalyst.
The waste catalyst containing Vanadium are divided into two types:
One is used for refining desulphurization catalyst in petroleum refining, desulfurization process, the Vanadium in crude oil in the form of V3S4 deposition on catalyst. The other is the catalyst for sulfuric acid industry, Vanadium catalyst in contact sulfuric acid production process, the sulfur dioxide into three sulfur trioxide. Due to the use of the process, the gas with water, fog, dust and arsenic, fluorine has toxic effect on it, tetravalent Vanadium the active component of five of two Vanadium conversion of non activity, if the tetravalent Vanadium ratio reached a certain level, causes the Vanadium catalyst failure, which need to be replaced.
2. Recovery of Vanadium from vanadiferous asphalt.
Asphalt tar oil, the tar used as fuel in the ashes, Vanadium in Vanadium raw materials, can be used as. With the NaOH solution leaching, when the concentration of NaOH reached 30%, and the fuel ash ratio reaches a certain value, in the range of 100 to 110 ℃ hybrid 2h, the leaching rate of Vanadium can reach 94%. After filtering, the sodium vanadate solution is neutralized with sulfuric acid to pH = 8, adding ammonium salts obtained Ammonium Metavanadate precipitation, recovery rate of close to 85%. Ammonium Metavanadate sediment is filtered after drying, calcining to obtain V205. After Vanadium precipitation liquid containing 0.2 to L G / L V, the pH = 5 the remaining solvent recovery, exchange of Vanadium by anion, the Vanadium concentration in the filtrate to 1mg / L.
3. Recovery of Vanadium from alumina production.
Bauxite is usually also contain a small amount of Vanadium. With the Bayer process of bauxite, due to the effect of alkali, about 30% of Vanadium into leaching solution. When the aluminum hydroxide from sodium aluminate solution precipitation, Vanadium in the mother liquor, leaching operation returns the bauxite, so that the Vanadium in solution concentration.
Vanadium in solution enriched too much on aluminum production is harmful, in addition to the precipitation so must use slow cooling or air way of Vanadium in Vanadium containing sludge form. The Vanadium containing mud called Bayer mud, five oxidation which contained 6 to 20% two V, can be used as raw material for extracting Vanadium.

Incandescent lamp is a kind of thermal electric light source, its working principle is high temperature radiation illuminated by the filament. When you are working in the filament temperature is very high (about 2700 ℃), is bound to cause part of the Tungsten filament evaporation. Evaporation filament tapering, and appear uneven thickness. With the loss degree of increasing, the filament will burn out in starting or work, end of its service life.
Especially the moment, opening the lamp current is far above the rated current of the light bulb. This current is about 0.007 seconds, in such a short time, the filament temperature soared, the filament produce "hot spots", some weak positions of Tungsten excessive evaporation, gradually (through frequent switch) Tungsten filament in these places becomes more and more thin, so easily broken wires occur when turn on the light.
Incandescent lamp as the light of the application is still very common, one of the research and improvement of it never pause. Among them, how to prolong the service life of incandescent lamp Tungsten wire inside the is one of the important interest and the purpose of people to study, such as halogen lamp the emergence of a certain extent, prolong the life span of the Tungsten lamp. But in essence, Tungsten wire in hot state is more or less will happen Tungsten turned fine Tungsten atoms (and uneven) sublimation phenomenon. Understanding this process for prolonging the life of the lamp from the essence is decided to significance. A lot of literature, at the mention of Tungsten filament lamp damage reason mentioned filament of so-called "hot effect".
Theoretically, due to the evaporation and temperature index of the Tungsten atoms never to 0 (index), on the other hand, the Tungsten wire is fine, the greater the resistance, the smaller the bulb power, therefore, a perfect straight Tungsten wire is not destroyed, just as the use, the light bulb is more and more dark. And, in fact, Tungsten filament on the total defective, typical is, there's always a part of the Tungsten fine than other places.
Most people have such experience, at the moment of bulb damage, is not a whole article Tungsten all evaporate, but the sudden rupture of a point, and usually accompanied by a certain point relative to other bulb lights suddenly. Most such fracture of Tungsten light bulb in the use of certain skills will be put together again, you can also use a short period of time, at least to flash (usually do not imitate). In fact, this case is the "hot spot effect".

Polyvinyl Alchohol fiber is with Polyvinyl Alchohol as raw materials of synthetic fiber spinning. The fiber obtained by formaldehyde treatment of vinyl alcohol acetal fiber, vinylon Chinese said, internationally known Vigny lun. Low molecular weight Polyvinyl Alchohol as raw material by spinning fiber is soluble in water, soluble in water of Polyvinyl Alchohol fiber. Polyvinyl Alchohol fiber generally does not have the necessary water resistance, little value in practical application. Polyvinyl formal fiber with soft, warm characteristics, especially the moisture absorption rate (up to 5%) in synthetic fiber in various varieties is relatively high, so it is called synthetic cotton, but the poor heat resistance, softening point is only 120 ℃.
The polymerization of vinyl acetate:
Vinyl alcohol free and extremely unstable, can not exist alone, so to obtain the practical value of Polyvinyl Alchohol, usually with vinyl monomer polymerization and alcoholysis and hydrolysis, made of Polyvinyl Alchohol.
1. Vinyl acetate preparation:
At present, the vinyl acetate synthesis is mainly acetylene and ethylene method.
1). Acetylene method:
Acetylene method with acetylene and acetic acid as raw materials, at about 200 ℃, pressure to the gas to the catalyst of zinc acetate supported on reaction of vinyl acetate with active carbon and so on.
2). Ethylene method:
Ethylene law to ethylene and acetic acid as raw materials, using palladium gold catalyst, potassium acetate or sodium acetate as catalyst, activated alumina or silica gel as the carrier, in more than 100 ℃, pressure reaction of acetic ethylene.
2. Vinyl acetate preparation:
Vinyl susceptible to free radical polymerization. Under the action of the initiator, vinyl acetate polymerization conditions can occur in slow and under. Preparation of Polyvinyl Alchohol fiber is using poly vinyl acetate, usually using methanol as solvent by solvent polymerization.
The preparation of Polyvinyl Alchohol:
At present the production of Polyvinyl Alchohol fiber is poly vinyl acetate in methanol or sodium hydroxide under the action of alcoholysis reaction.