Abstract:
A method is shown for manufacturing an aerated autoclaved concrete material. A quick-stiffening mixture is prepared by combining a silica containing material, quicklime, a rising agent, gypsum, cement and water. The mixture is deposited into a mold and is allowed to form a stiffened body. The stiffened body is removed from the mold and placed in an autoclave station in which it is steam cured at elevated temperature and pressure. The quicklime which is used to form the quick-stiffening mixture is modified with a chemical modifier to provide a desired degree of chemical reactivity in the quick-stiffening mixture.
Abstract:
A high solids lime slurry is prepared by either slaking quicklime or by slurrying dry, hydrated lime. The high solids lime slurry is mixed (15) with crushed aggregate (13) which has been collected by scraping (11) the top surface of an old roadway. The treated aggregate is deposited (17) onto the old roadway and compacted (19) to form a new roadway.
Abstract:
A method is shown for controlling the presence of soluble sulfate ions in a lime slaking operation in which a source of quicklime is combined with slaking water to form calcium hydroxide product. A complexing agent is added to either the quicklime or the slaking water which is effective to tie up the soluble sulfate ions otherwise available in solution, whereby the agglomeration of calcium hydroxide product is acceptably controlled.
Abstract:
A method of treating aggregate for use in hot mix asphalt compositions to promote adhesion between the aggregate material and bituminous binder by mixing together in a mixing tank (12) unslaked quicklime and an aqueous slaking medium to form a quicklime slurry and pumping the slurry through a conduit (70) to be mixed with aggregate from a feed bin (75) at a pugmill (74) of a hot asphalt plant.
Abstract:
A method is shown for producing food grade hydrated lime. A source of raw, hydrated lime is first passed through a classification step which divides the raw hydrated lime into a first fine stream and a first coarse stream. The first coarse stream is then passed to a grinder which produces a ground coarse product. The first fine stream is separated out from the first coarse stream and, without combining the first fine stream with the first coarse stream or with the ground coarse product, is removed to produce a very fine sized product which meets CODEX chemical specifications.
Abstract translation:示出了用于生产食品级熟石灰的方法。 原始熟石灰的来源首先通过分级步骤,该分级步骤将原始熟石灰分成第一细流和第一粗流。 然后将第一粗粒物流传送到研磨机,该研磨机产生磨碎的粗产品。 将第一细物流从第一粗物流中分离出来,并且不将第一细物流与第一粗物流或磨碎的粗物质混合,将其除去以产生符合CODEX化学规格的非常精细尺寸的产物。 p >
Abstract:
A method of treating concrete pipe (10) is carried out by providing an aqueous lime slurry supply having a lime solids content above 35 % by weight of the slurry. This is mixed within an amount of dispersing agent and may contain an alkali metal hydroxide so that the slurry has a pumpable viscosity. A spray assembly (28) is located within the interior of the pipe. The lime slurry is pumped from this lime slurry supply through the spray assembly (28) so that the lime slurry is applied to the interior surface of the pipe to neutralize acids thereon. Applying the lime spray also provides a protective coating of the lime slurry on the interior surfaces of the pipe.
Abstract:
Flue gases exhausted from a lime kiln (10) containing lime kiln dust are treated to produce a high purity calcium carbonate precipitate. This is accomplished by passing the flue gases from the lime kiln (10) through a kiln dust separator (12) so that lime kiln dust containing calcium oxide is removed from the remaining flue gas (15). The lime kiln dust is mixed with water so that an aqueous suspension of the lime kiln dust is formed. Quicklime or calcium oxide in the lime kiln dust is thus hydrated to form calcium hydroxide. The solids within the suspension are then allowed to settle in settling tank (14) so that a clear, saturated solution of calcium hydroxide having a pH of about 12.4 is formed. This solution is then contacted with carbon dioxide gas in reaction tank (16) so that the calcium hydroxide reacts to form a high purity calcium carbonate precipitate. This high purity calcium carbonate precipitate is then allowed to settle from supernatant water of the solution in thickener tank (20). The high purity calcium carbonate is separated from the supernatant water, while the supernatant water is recycled through conduit (24) and used as the water mixed with the lime kiln dust to form the aqueous suspension.
Abstract:
A composition for a pumpable lime slurry which is adapted for use as a replacement for caustic solutions is formed by combining a dispersing agent in lime and water to form an aqueous slurry. The amount of lime used is between 35 to 55 % by weight of the slurry. The dispersing agent, which is an anionic polyelectrolyte, such as polyacrylic, polycarboxylic acids and alkali metal salts thereof, is added in an amount between 0.1 to 3 % by weight of the lime. To this is added an alkali metal hydroxide of 0.1 to 1.5 % by weight of lime. The order of addition of the alkali metal hydroxide is important. The later addition of the alkali metal hydroxide results in a decreased viscosity so that a lower amount of dispersing agent is required.