Abstract: Substance particulate in the general size range of minus 30 Mesh U.S. Standard to about 1 micron is separated into portions based on the densities of those components making up the total by drying to about 1% moisture and air conveying the substance through a duct in which the material assumes a stratified arrangement dictated by particle density. Means are provided by air duct configuration and partial flow diversion to remove appropriate laminar segments of the air-solids mixture.Light, medium and heavy ash and pyritic Sulfur in substantial percentages can be removed from bituminous coal fines embodying this principle in a negative air atmosphere. After beneficiation of bituminous coal fines any undesired pyritic or organic Sulfur can be contained by intimately mixing calcium hydroxide with the coal in the amount of 2.24 parts of calcium hydroxide to one (1) part of Sulfur by weight.

Abstract: Strong aggregates of high density are produced from fine particles by heating said particles, then combining a binder solution comprising a saturated, dendritic crystal-forming aqueous sodium chloride solution heated to a temperature below the temperature of the heated particles, mixing thoroughly said heated particles and said heated binder solution in a ratio of 10 to 20 grams, preferably 14 to 18 grams, of particles per milliliter of binder solution, shaping the resulting mixture under pressure and cooling the shaped mixture to recrystallize said binder solution and provide said agglomerate.Aggregates of high porosity and strength can be prepared from siliceous materials such as fly ash by heating the product agglomerated to a temperature of 1600.degree.F-1825.degree.F.