44 results about "Elemental chlorine free" patented technology

The invention relates to the field of technical ceramics and specifically relates to a method of synthesis for aluminum oxides of different crystalline structure and to the products obtained by the method. The aim of the invention is to provide a method of producing redispersible nanoparticulate corundum and nanoporous Al2O3 sintered products, the method using precursors and being viable on a commercial scale. To this aim, inter alia, a method of producing redispersible nanoparticulate corundum of an average particle size of D50<100 nm is used which method includes the addition of crystal nuclei. According to the method, organic or chlorine-free inorganic precursors are dissolved or processed to a sol and hydrolyzed. The substance is then dried and calcinated at temperatures of between 350 and 650° C. and is then further heated by increasing the temperature to ≦950° C. The aim of the invention is also attained by using a method of producing nanoporous Al2O3 sintered products according to which organic or chlorine-free inorganic precursors are dissolved or processed to a sol and hydrolyzed. The substance is then dried and calcinated at temperatures of between 350 and 750° C.

The invention provides a method for carrying out elemental chlorine free (ECF) multistage bleaching on masson pine kraft pulp by using glyoxal. The method is characterized by firstly adopting chlorine dioxide to carry out delignification on the unbleached masson pine kraft pulp; then utilizing sodium hydroxide to carry out alkali extraction on the masson pine kraft pulp after delignification; then using chlorine dioxide to carry out delignification on the masson pine kraft pulp; and finally adopting hydrogen peroxide to bleach the masson pine kraft pulp to obtain the masson pine ECF pulp with high whiteness and excellent physical indexes. The method has the following beneficial effects: the whiteness of the prepared masson pine kraft pulp can reach 88.36% ISO, the Kappa number is 5.02 and the yield is about 90.28%; and the masson pine kraft pulp bleached by DEDP is used for manufacturing the handsheet and the tensile index is 40.08N.m / g, the tear index is 12.80mN.m<2> / g and the burst index is 3.45kPa.m<2> / g, thus showing that the finished paper has better physical strength.

The invention relates to a process for bleaching needlebush and hardwood mixed chemical pulp stewed by using a sodium hydroxide anthraquinone method. The process comprises the steps of: mixing needlebush chemical pulp stewed by using the sodium hydroxide anthraquinone method with hardwood chemical pulp stewed by using the sodium hydroxide anthraquinone method in a mass ratio which ranges from 3:7to 7:3; and then performing high-whiteness bleaching by employing an ECF (elemental chlorine free) bleaching process having a bleaching working procedure of O1-O2-D0-OEP-D1-D2 or O1-O2-D0-OEP-D1. In the invention, the dosage of consumed chemicals in an entire process is equal to or a little lower than that of a process in which paper pulp is respectively stewed and respectively bleached. The two kinds of stewed crude pulp are similar in Kappa number, therefore other conditions of the bleaching process are milder, and the pulp provided by the invention is easier to bleach than the paper pulp with great hardness difference. Both the whiteness stability of the bleached paper pulp and various physical indexes such as burst index, fracture length, tearing index, folding strength and the like of made paper are better.

A method for plasma-etching a magnetic film and plasma-cleaning, in which deposits in an etching processing chamber are efficiently removed while corrosion of a wafer is suppressed, is provided. A plasma processing method for plasma-etching a to-be-processed substrate having a magnetic film in an etching processing chamber includes the steps of plasma-etching the magnetic film using a first gas not containing chlorine, transferring out the to-be-processed substrate from the etching processing chamber, first plasma-cleaning of the etching processing chamber using a second gas containing chlorine, and second plasma-cleaning using a third gas containing hydrogen after the first plasma cleaning.

The invention relates to an elemental chlorine free bleaching method. In the method, dioxin and AOX are removed from the source by adopting D section bleaching and P section bleaching. The straw pulp is bleached by adopting the elemental chlorine free bleaching method, so that the problem that wastewater obtained by bleaching by the chlorine-containing bleaching method is most severely polluted is solved; and the bleaching process is simple and practicable. Each index of the bleached stuff can be compared with that of broadleaf wood pulp.

The invention discloses a method for reducing the content of AOX in chlorine dioxide bleaching wastewater of bagasse pulp. With bagasse as a raw material, bagasse is treated by using hot water pre-extraction technology; pretreated bagasse enters an elemental chlorine-free bleaching phase after a cooking and steaming procedure, and chlorine dioxide is used as a main bleaching agent; and after a section of chlorine dioxide bleaching procedure, wherein the usage amount of chlorine dioxide is 1.6% of the mass of absolute dry bagasse pulp, the content of AOX in bleaching wastewater is detected. Compared with the prior art, the method provided by the invention has the advantage that the content of AOX in bleaching wastewater is greatly reduced.

Provided is a phenol resin foam body which comprises a phenol resin and a foaming agent that includes a chlorinated hydrofluoroolefin and / or a non-chlorinated hydrofluoroolefin. The phenol resin foam body has a density of 10 to 150 kg / m3, a thermal conductivity in a 10 DEG C environment of 0.0175 W / m.k or less, and a thermal conductivity in a 23 DEG C environment of 0.0185 W / m.k or less.

The invention discloses a wheat straw pulp elemental-chlorine-free bleaching wastewater recycling method which is characterized in that a paper pulp bleaching mode is DQP three-section bleaching, and the whole washing wastewater of pulp from hydrogen peroxide (P) section bleaching is reused, without being processed, in washing pulp from chlorine dioxide (D) section bleaching. The specific method is as follows: after the washing wastewater of pulp from the P section bleaching is reused in the D section bleaching, the pulp is diluted to the washing pulp concentration of 0.5-2%; the pulp is fully mixed and washed and then is concentrated to 15-18%; and the concentrated pulp is diluted with clear water and then is processed in a Q section. The amount of residual bleached chemicals in washing water from the P section is no less than 40%. By the method of directly recycling P-section bleaching wastewater in washing pulp from D-section bleaching without being processed, water consumption during the wheat straw pulp bleaching process and yield of bleaching wastewater can be reduced effectively. In addition, dosage of a bleaching agent can be decreased remarkably, pollution load can be reduced, and performance of the bleached pulp is basically not influenced. Heat energy of wastewater from the P section also can be utilized, and energy consumption of the bleaching section can be reduced effectively.

A method of manufacturing a fluorine-doped glass preform for an optical fiber, comprising: exposing a soot preform (11) in a first elongated chamber (28; 44) of a first furnace (30; 40) to an atmosphere containing In an atmosphere of fluorine gas and substantially free of chlorine to obtain a fluorine-doped soot preform, the first elongated chamber (28; 44) has a single isothermal hot zone maintained at a doping temperature of 800°C to 1200°C (33; 53); exposing the fluorine-doped soot preform (11) in a second elongated chamber (61) of a second furnace (60) to an atmosphere comprising a gas containing chlorine and substantially free of fluorine to make It dehydrates, and the second elongated chamber has an upper thermal zone (66') at a dehydration temperature of 1000°C to 1350°C and a lower thermal zone (67') at a consolidation temperature of 1500°C to 1650°C, wherein Dehydration takes place in the upper hot zone (66') of the second furnace, and the fluorine-doped soot preform (11) is consolidated by moving it down into the lower hot zone of the second furnace to obtain fluorine-doped Glass preforms.

The invention relates to a clean fuel gas generating agent, which is characterized in that chlorine-free 1,1-diamino-2,2-dinitroethylene is introduced into a formula of the fuel gas generating agent,and serves as a clean oxidizing agent to replace ammonium perchlorate, and the problems that the fuel gas generating agent is large in combustion smoke and large in residue amount are solved. The clean fuel gas generating agent disclosed by the invention has the characteristics of being clean in gas, low in residue, low in characteristic signal, safe, insensitive and the like. The fuel gas generating agent is applied to a power source of an aircraft, so that the combat effectiveness and the war survival ability of the aircraft are greatly improved, and the fuel gas generating agent has an extremely wide application prospect.

The invention provides a sliding member which is able to further improve wearability and is not maintained for a long time by using substitute refrigerant without chlorine or natural refrigerant and a scroll motor compressor using the sliding member. The invention forms an oxydizing membrane layer (14) on the surface of the sliding member (8) formed by sintered iron, and forms an intermediate layer (15) on the oxidizing membrane layer (14), and forms an oxide layer (14A) and forms a hard carbon membrane layer (16) on the intermediate layer (15). As above, the surface of the sliding member (8)is orderly formed with the oxydizing membrane layer (14), the oxide layer (14A), the intermediate layer (15) and the hard carbon membrane layer (16), so as to contact the hard carbon membrane layer (16) with excellent wearability and low friction with the surface of the sliding member (8) and not to maintain for a long time.

The invention relates to an inorganic electrolytic coagulant and a soil reconstruction method using the inorganic electrolytic coagulant. Mix phosphonic acid and magnesium sulfate in a chlorine-free solvent and stir for several minutes, then mix aluminum sulfate and polyferrous sulfate, and stir for several minutes to obtain an inorganic electrolytic coagulant. The inorganic electrolytic coagulant and soil particle enhancer and pH The aqueous solution mixed with the regulator is added to the polluted bottom mud of lakes, bays, and rivers obtained by dredging, thereby changing the bottom mud into good soil.

This invention relates to products useful in friction-reducing extreme-pressure lubricating applications such as internal combustion engines, gear oils and applications which involve rubbing metallic moving parts. The invention includes additive blends and a process of using synergistic combinations of nitro compounds with non-chlorine containing additives such as sulfur-containing moieties and phosphorus-containing moieties.