Apparatus for the uniform distribution of material issuing from blast pipe lines has a terminal distributor arranged directly on the discharge end of a horizontal or slightly rising conveyor pipe line, with the distributor including a drivable and swingable discharge trough. The discharge trough is mounted for oscillation, in a predetermined adjustable range, about the axis of the conveyor pipe to direct the material at an angle to the axis either laterally or downwardly. The conveyor pipe includes an intermediate section and a terminal section having a diameter larger than that of the intermediate section. A guide rail extends above the material receiving area and mounts the terminal section for reciprocation parallel to its axis with the major part of its length being telescopable over the intermediate section. The terminal section may be designed as an elongated hood with a detachable bottom wall which is detached from the hood as the terminal section is retracted and which is attached to the hood as the terminal section is extended.

Determinations of the aqueous solubilities of kaolinite at pH 4, and of five smectite minerals in suspensions set between pH 5 and 8, were undertaken with mineral suspensions adjusted to approach equilibrium from over- and undersaturation. After 1,237 days, Dry Branch, Georgia kaolinite suspensions attained equilibrium solubility with respect to the kaolinite, for which Keq = (2.72 ± 0.35) × 107. The experimentally determined Gibbs free energy of formation (ΔGf,2980) for the kaolinite is −3,789.51 ± 6.60 kj mol−1. Equilibrium solubilities could not be determined for the smectites because the composition of the solution phase in the smectite suspensions appeared to be controlled by the formation of gibbsite or amorphous aluminum hydroxide and not by the smectites, preventing attempts to determine valid ΔGf0 values for these complex aluminosilicate clay minerals. Reported solubility-based ΔGf0 determinations for smectites and other variable composition aluminosilicate clay minerals are shown to be invalid because of experimental deficiencies and of conceptual flaws arising from the nature of the minerals themselves. Because of the variable composition of smectites and similar minerals, it is concluded that reliable equilibrium solubilities and solubility-derived ΔGf0 values can neither be rigorously determined by conventional experimental procedures, nor applied in equilibriabased models of smectite-water interactions.

Concentrations of mononuclear dissolved Al are determined in samples of natural waters and of solutions separated from experimental suspensions of clay minerals, by solvent extraction and spectrophotometry of aluminum 8-hydroxyquinoline. Samples are treated with a solution of 8-hydroxyquinoline buffered at pH 5.0 by sodium acetate-acetic acid. The resulting Al-hydroxyquinoline complex is extracted immediately into 2.00 ml toluene, to prevent inclusion of secondary mononuclear Al released from poly-nuclear Al(OH)x ions or aluminous solids. After centrifugation-separation of the toluene and aqueous phases, the overlying toluene layer is transferred to a spectrophotometer equipped with a miniature fixed quartz cell. A detection limit of 0.2 μg Al l−1 can be attained with 100-ml samples, and at 1.0 μg Al l−1, the analytical uncertainty is ± 10% or less. Preliminary extractions with chloroform solutions of diethylammonium diethyldithiocarbamate eliminate interferences due to dissolved V, Fe, Ni, Cu, Ga, Mo and U. Extracting the Al-hydroxyquinoline complex at pH 8.3 eliminates any interference due to F. The procedure was used to measure the solubility of gibbsite over the pH range 5–8.