5 results about "Dilute acid" patented technology

In the biomass hydrolyzing process of preparing reductive monosaccharide, biomass material is hydrolyzed at 100-200 deg.c in the dilute acid catalyst, and the hydrolysate stays in the reactor for 5-40 min. The hydrolysate is divided into three parts based on dydrolysis order and hdyrolysate concentration and the three parts are used as the hydrolysis product and acid solution for the next batch of material to hydrolyze. The partial circulation of the hydrolysate can raise the concentration of monosaccharide in the hydrolysate from 4% to 6% and reduce acid consumption.

The invention relates to a nickel-containing high-cobalt sulfide leaching technology. A leaching liquor rich in metal cobalt obtained through atmospheric pressure preheating and pressure leaching can directly enter a cobalt production system. The technology comprises the following technical steps of: (1) slurrying minerals in 10-20 g/l dilute acid solution, controlling the ratio of dilute acid volume to material mass at 6:1, and controlling slurrying temperature at 40-50 DEG C, slurrying time at 2-3 h and the concentration of slurrying end point acid at 5-15 g/l; (2) controlling the temperature of atmospheric pressure preheating at 80-85 DEG C; (3) controlling pressure leaching, controlling the ratio of dilute acid volume to material mass at 6:1, reaction temperature at 145-165 DEG C, and leaching partial pressure oxygen at 0.20-0.25 Mpa and reaction time at 6-8 h. In the invention, a nickel and cobalt sulfate solution containing more than 50 g/l cobalt is obtained, i.e. more than 98% of Ni and Co in the nickel-containing high-cobalt sulfide material is leached out to enter the solution.

The invention discloses a straight-chain liquid AKD surface sizing agent and a preparation method thereof. The straight-chain liquid AKD surface sizing agent is prepared from the following raw materials in parts by weight, 100-200 parts of starch, 1000-2000 parts of water, 4-8 parts of sodium hydroxide, 25-50 parts of a cationic etherifying agent, 5-10 parts of a dilute acid, 15-30 parts of a cationic monomer, 25-50 parts of acrylamide, 1-2 parts of an initiator, 5-10 parts of a dispersing agent, 20-50 parts of an AKD special cationic polymer emulsifier, and 60-150 parts of liquid AKD. The molecular structure of the straight-chain liquid AKD adopted by the invention has a lactone ring structure; reacting under neutral and alkaline conditions; the reaction functional groups and hydroxyl groups on fiber molecules are subjected to esterification reaction to be firmly bonded on the surfaces of the fibers; the hydrophobic long-chain fatty group turns to the paper surface, so that the hydrophobic effect is obtained, the stability and the sizing effect of the AKD surface sizing agent are remarkably improved by adding the AKD special cationic polymer emulsifier, meanwhile, the hydrolysis and migration tendency of AKD is limited, and AKD latex is well protected.

The invention discloses a preparation method of alumina gel and polyaluminium chloride, and belongs to the technical field of alumina gel and polyaluminium chloride preparation. The invention mainly provides a preparation method of high-activity alumina gel and high-purity, low-energy-consumption and waste-residue-free polyaluminum chloride. The method comprises the following steps: neutralizing an aluminum salt solution or dilute acid with sodium aluminate, potassium aluminate or dilute alkali solution within a certain period of time until the pH value is 4-8 to obtain high-activity alumina gel, and keeping the temperature of the alumina gel and a one-step solution for preparing polyaluminum chloride at 65-95 DEG C for 0.5-2 hours to obtain polyaluminum chloride with the basicity of 90% or below. The alumina gel prepared by the method is high-purity amorphous hydrated alumina, when the polyaluminum chloride is further prepared, the solution is clear and transparent, filter pressing orsedimentation is not needed, no waste residue is generated, the preparation process does not need cooling, the production time is short, the energy consumption is low, and the purity of the finishedproduct polyaluminum chloride is high.

The invention discloses a dismounting-and-washing-free descaling method for a dilute acid plate heat exchanger. The dilute acid plate heat exchanger is adjusted once after normally working for two months, specifically, a hot dilute sulphuric acid inlet and a cold circulating process water inlet of the dilute acid plate heat exchanger are exchanged, and meanwhile a hot dilute sulphuric acid outlet and a cold circulating process water outlet are exchanged, so that cold circulating process water is fed into a flow channel where hot dilute sulphuric acid is fed originally, and hot dilute sulphuric acid is fed into a flow channel where cold circulating process water is fed originally; and after the dilute acid plate heat exchanger works for four work hours after the exchange, the hot dilute sulphuric acid inlet and outlet and the cold circulating process water inlet and outlet are exchanged correspondingly to recover the original state. According to the method, operation is simple, consumed time is short, the heat exchange efficiency of the heat exchanger is ensured, and normal production is not influenced. According to the method, the link of dismounting and washing plates is omitted, damage to rubber sealing strips and the complex procedure for pasting the rubber strips again are avoided, corresponding material cost is omitted, labor input is reduced, and cessation of production is not needed. Compared with conventional methods, the method can prolong the service life of equipment by three to five years.