35results about How to "Strong resistance to hydration" patented technology

The invention discloses a magnesium oxide whisker in-situ synthesis magnesium aluminate spinel enhanced magnesium-oxide-based foam ceramic filter with chemical stability and excellent thermal shock resistance capable of sintering in a low temperature and a preparation method thereof. The preparation method comprises the following steps: (1) according to a mass percent, compounding by 15%-25% of nano-aluminum sol, 0.8%-1.5% of rheological agent, and the balance of magnesia ceramics powder containing magnesium oxide whisker, adding deionized water, ball-milling, uniformly mixing, and preparing ceramic slurry of which the solid content is 60%-70% through vacuum exhaust; (2) immerging a polyurethane foamed plastic template in the ceramic slurry, extruding the polyurethane foamed plastic template through a roller press so as to remove redundant immerging slurry, preparing a biscuit, heating the biscuit to 80-120 DEG C, and drying; and (3) placing the dried biscuit in a sintering furnace, warming to 1400-1600 DEG C, and sintering in a high temperature, cooling to room temperature along with the furnace, to obtain the magnesium-oxide-based foam ceramic filter.

The invention relates to the field of preparation of refractory materials, particularly a method for preparing high-quality calcium magnesia by superhigh-temperature calcination, which is characterized by comprising the following steps: preparing dolomite and magnesite into a raw material in which the CaO content is 15-20 wt% and the MgO content is 80-85%; adding the raw material into a ball milling tank, grinding and mixing, and meanwhile, adding water to carry out slaking and slurrying; and drying the slurry, adding calcium lignosulphonate, evenly mixing, pressing into green bricks, and calcining. The calcination process comprises the following steps: heating to 1100 DEG C, keeping the temperature for 3-5 hours, heating to the final calcination temperature of 2000-2200 DEG C, keeping the temperature for 5-7 hours, vacuumizing, cooling with water to 1000 DEG C, introducing protective hydrogen, and continuing cooling with water to room temperature. Compared with the prior art, the calcium magnesia has the advantages of high hydration resistance and high corrosion resistance, thereby basically solving the problem of high hydration tendency in the magnesium-calcium refractory material, and facilitating the storage, transportation, building and the like in future.

The invention belongs to the technical field of coal chemical industry sulfur-tolerant shift, and particularly relates to a low temperature sulfur-tolerant shift catalyst and a preparation method thereof. The low temperature sulfur-tolerant shift catalyst comprises a carrier and an active component, and is characterized in that attapulgite clay is adopted as the carrier, the carrier is added with a magnesium-containing powdery solid compound and a titanium-containing powdery solid compound, the active component is a metal oxide of Co, Ni and Mo, and an active auxiliary agent is added. The low temperature sulfur-tolerant shift catalyst has characteristics of good structure stability, strong hydration resistance, good low temperature activity, good activity stability, low active component loss rate and long service life, and can meet requirements of the industrial sulfur-tolerant shift work section low temperature condition on the catalyst. In addition, the raw material adopts the attapulgite clay with characteristics of wide source and low cost so as to substantially reduce the catalyst preparation cost, provide an effective approach for comprehensive utilization of the attapulgite clay, and provide good economic benefits and good environmental protection benefits.

The invention provides a sulfur-resistant shift reaction equipment and a sulfur-resistant shift process method. The sulfur-resistant shift reaction equipment includes a first-stage shift reactor, a second-stage shift reactor, and a third-stage shift reactor connected in series; wherein, the first-stage shift reactor is filled with MgAl2O4 as a carrier, and A catalyst with CoO and MoO3 as the main active components; the second-stage shift reactor is filled with a catalyst with MgAl2O4 as the carrier, CoO and MoO3 as the main active components, and rare earth oxides as active promoters; The three-stage shift reactor is loaded with a catalyst with MgAl2O4 or Al2O3 as the carrier, CoO and MoO3 as the main active components, and K2O as the active promoter. The sulfur-resistant shift reaction equipment provided by the invention can carry out sulfur-resistant CO shift for feed gas with high CO concentration, high steam-gas ratio, oil pollution and dust, and the sulfur-resistant shift process method provided by the invention has the advantages of simple design, safe operation, It is not easy to "fly temperature" and has the characteristics of low investment.

The invention discloses a method for preparing a hydration-resistant and thermal-shock-resistant calcium oxide crucible by a dry process. The method comprises the following steps: purifying quicklime lumps, and crushing and fining the quicklime lumps with calcium oxide purity higher than 96%; mixing the quicklime fines with additives so as to form a mixture, and then, pressing the mixture into brick-shaped products; carrying out first-time temperature-controlled sintering on the brick-shaped products; crushing the sintered material obtained after first-time sintering, carrying out screening, then, carrying out proportioning proportionally, and carrying out uniform mixing so as to form clinker; loading the clinker obtained through carrying out uniform mixing in the step (4) to a crucible die, carrying out compaction on a vibrating platform, and carrying out pressing by a cold isostatic press; and putting a calcium oxide crucible green body in an electric furnace, carrying out second-time temperature-controlled sintering according to a secondary temperature-control curve, thereby obtaining a calcium oxide crucible product. The calcium oxide crucible prepared by using the method has the advantages that the hydration resistance is higher, the thermal-shock resistance is better, the sintering is denser, and the strength of the crucible is good.

The invention relates to a CO (carbon monoxide) sulfur tolerant shift catalyst applicable to a high pressure process and a preparation method thereof. The CO sulfur tolerant shift catalyst applicable to the high pressure process comprises a carrier and a catalyst active component, wherein the carrier is prepared from the following materials by mass percent: 5-40% of modified bauxite powder, 20-60% of pseudoboehmite or aluminum nitrate, and 10-40% of magnesium oxide or magnesium hydroxide; the catalyst active component comprises CoO, MoO3 and CeO2; and CoO is 0.5-5% of the weight of the catalyst, MoO3 is 1.0-15% of the weight of the catalyst and CeO2 is 0.3-2% of the weight of the catalyst. The preparation method comprises the following steps: raw materials mixing; kneading; strip extruding; roasting; isometric impregnation, and the like. The preparation process is simple and no waste water is discharged. The prepared catalyst carrier has excellent hydration resisting property and strength. The activating temperature of the catalyst is low. Under the conditions of high pressure, high gas to steam ratio and high temperature, the catalyst has excellent thermal stability.

The invention provides a sulfur-tolerant shift catalyst using cobalt-magnesium-aluminum hydrotalcite as a precursor, using CoMgAl-LDO as a carrier, and using MoO3 as an active component. The carrier CoMgAl-LDO is based on cobalt-magnesium-aluminum hydrotalcite. The precursor is prepared after roasting, and has the characteristics of uniform cobalt dispersion, suitable surface alkalinity and uniform distribution of pore structure. The catalyst prepared by further using the carrier CoMgAl-LDO to impregnate the Mo active component can make the Co and Mo components All are highly dispersed, in which the Co component is evenly distributed in the interior and surface of the catalyst carrier, and a good interaction is formed between Co and Mo, and the catalyst has high catalytic activity in a wide temperature range of 250-450°C , high thermal stability, strong hydration resistance, not only suitable for high temperature, high pressure and high steam-gas ratio conversion conditions, but also suitable for medium pressure and low temperature conversion process.

The invention discloses an alumina short fiber-reinforced magnesium oxide-based crucible which is excellent in chemical stability and thermal shock resistance, and can realize sintering at a low temperature and a preparation method thereof, the method comprises the following steps: (1) proportioning, by mass, 15% to 25% of nano-aluminum sol, 0.8% to 1.5% of a rheological agent, and balance of electro-fused magnesium oxide ceramic powder containing nano-lanthana and alumina short fiber, adding an appropriate amount of deionized water, uniformly mixing by ball milling, and vacuum degassing to obtain a ceramic slurry having a solid content of 70% to 80%; (2) preparing a crucible biscuit; (3) preparing a crucible blank; and (4) putting the magnesium oxide-based crucible blank in the aluminum sol for vacuum impregnation treatment, grinding the surface, drying, performing high-temperature secondary sintering at a temperature of 1400 to 1600 DEG C, and cooling in a furnace to room temperatureto obtain the magnesia-based crucible.

The invention belongs to the technical field of refractories for steel smelting furnaces, and in particular relates to a zirconium composite high-performance electrofused magnesium-calcium zirconium brick and a manufacturing method thereof; the zirconium composite high-performance electrofused magnesium-calcium zirconium brick comprises 5-10% of electrofused magnesium-calcium zirconium sand with a partical size of 5-8mm, 20-35% of electrofused magnesium-calcium zirconium sand with a partical size of 2-5mm, 20-30% of electrofused magnesium-calcium zirconium sand with a partical size of 2-0.074mm, 10-15% of electrofused magnesium-calcium zirconium sand fine powder with a partical size of 0.074mm or less, 1-5% of electrofused magnesium sand with a partical size of 5-8mm, 1-10% of electrofused magnesium sand with a partical size of 2-5mm, 1-5% of electrofused magnesium sand with a partical size of 2-0.074mm, 5-10% of electrofused magnesium sand fine powder with a partical size of 0.074mm or less, 5-10% of electrofused magnesium sand super-fine powder with a partical size of 0.037mm or less, 0.5-1.2% of calcium stabilized zirconia with a partical size of 0.5mm or less, 0.5-2% of metal calcium powder with a partical size of 0.088mm or less, 0.1-0.5% of silica fume with a partical size of 0.003mm or less and 2-5% of a binder. The method can obviously improve the physical and chemical performance indexes of the magnesium-calcium zirconium brick, anti-penetration, anti-erosion, anti-erosion and anti-spalling and other use performances of the magnesium-calcium zirconium brick can be improved, and most importantly, the magnesium-calcium zirconium brick can meet the requirements of current smelting conditions.