摘要:
A process for making high-strength aggregates including hydrating calcium oxide containing coal combustion ash for a sufficient period of time to convert a high percentage of the calcium oxide to calcium hydroxide prior to forming the aggregates and curing the aggregates in high humidity. The moisture of the hydrated material is monitored to vary the hydration moisture to the desired set point. Further, the process involves producing high-strength aggregates from calcium hydroxide containing FGD ashes such as generated from duct sorbent injection and spray dryer processes.
摘要:
In a froth flotation beneficiation, the rate of addition of collector reagent is varied in response to the change in particle size effected by the beneficiation, as determined by comparing a size analysis of solid particles in one of the separated streams with a size analysis of solid particles in the feed stream.
摘要:
A method of separating fine coal particles from refuse particles comprising the step of:(a) providing a coal filter cake(b) forming a slurry of fine coal particles, refuse particles in a liquid mixture comprising water and organic liquid,(c) contacting said coal filter cake with said slurry,whereby a major portion of said water and a major portion of said refuse pass through said filter cake and a major portion of said organic liquid and a major portion of said fine coal particles pass across the top of said filter cake.
摘要:
A rotary drum assembly includes separate agglomerating and hardening drums that are rotated independently of each other. The agglomerating drum has a generally cylindrical configuration with an inner cylindrical wall. A scraper is rotatably positioned within the agglomerating drum in spaced relation to the inner cylindrical wall with its axis spaced from the axis of the drum. The scraper has a tubular body portion with a plurality of parallel rows of blades extending radially therefrom. Each of the rows extends lengthwise along substantially the entire length of the scaper body portion and follow a helical path having a single turn about the axis of the tubular body portion. The rows of blades thus make a single convolution about the scraper body portion. Drive means are provided to synchronously rotate the agglomerating drum and scraper with the scraper arranged to rotate at a preselected and different speed relative to the speed of the drum. Agglomerative material is introduced into the rotating agglomerating drum and forms a layer of agglomerative material on the drum inner cylindrical wall. The scraper is rotated in the same direction as the direction of rotation of the agglomerating drum and at a preselected synchronous speed with the agglomerating drum. The rows of parallel blades on the scraper form a plurality of spaced elongated generally longitudinal ridges and valleys in the layer of agglomerative material on the drum cylindrical wall. The ridges have a slight arcuate configuration and form less than a single convolution throughout the entire length of the agglomerating drum. The spaced elongated ridges in the layer of agglomerative material extend lengthwise in the drum substantially parallel to the axis of the drum and serve as longitudinally extending lifters to mix and agitate other particulate agglomerative materials introduced into the drum by lifting portions of the other particulate agglomerative material from the underside of the bed and depositing the material on the upper surface of the bed. This type of mixing promotes the formation of agglomerates having a preselected relatively narrow size range. The synchronous rotation of the scraper removes agglomerative material deposited on the surface of the elongated ridges and valleys formed in the layer of agglomerative material so that the desired ridge and valley configuration is maintained in the layer of agglomerative material.