Abstract: An apparatus for separating supernatant pollutant, such as oil, from a liquid, such as water is disclosed. The apparatus comprises a receiving tank and a separating tank. The receiving tank has a wall dividing the tank into a first vessel receiving the liquid mixture and having a self-adjusting weir, and a second vessel. The separating tank has a first receptacle separated from the first vessel by a partition along which the self-adjusting weir is located, and a second receptacle connected to the first receptacle. The first receptacle has an outlet for draining the supernatant, while the second receptacle and second vessel have outlets for draining the cleaned liquid.

Abstract: According to the invention, the grains of the hydrate slurry are separated by sedimentation where the dispersed bubbles of air are removed in course of the presizing, then a supplementary sizing is carried out. Preferably, a liquid free from hydrate grains is fed in to stream against the sinking grains. This liquid is advantageously the spent liquor of the hydrate filter. The apparatus according to the invention consists of a container with conical bottom, a feeding device, a slurry outlet stub and an overflow channel. The inlet stubs of the feeding device, however, are placed off-center and every stub is connected with a presizing equipment. This equipment is composed of a bundle of pipes and/or a pack of plates which are slop placed to geometrical axis: At the upper part of the presizing equipment there is a foam overflow apparatus. The bottom of each presizing equipment is connected with a common cone-frustum type deflector casing. The casing is concentric with the container.

Abstract: A method for determining charged energy states of a sample of a semiconductor or insulator material by using deep level transient spectroscopy.

Abstract: A Deep Level Transient Spectroscopy (DLTS) method in which a high frequency measuring signal is applied continuously on a semiconductor junction, and exciting pulses are generated which are coupled through fast semiconductor switching elements to the junction to alternatively bias the junction in reverse and forward (or slightly reverse) directions. The high frequency measuring signal passed through the junction is evaluated by means of a lock-in amplifier phase-locked with a constant phase angle, independent of the repetition rate of the exciting pulses.The evaluation circuits of the apparatus including the lock-in amplifier are controlled by switching elements driven by control signals generated from the exciting pulses.

Abstract: The invention relates to a new a method for simultaneous recovering vanadium, molybdenum and gallium from alumina factory aluminate liquors. The recovering is carried out in one step by electrolyzing an alumina factory aluminate liquor a temperature exceeding 70.degree. C. with a current density of from 400 to 1200 A/m.sup.2 using a low-melting liquid alloy as a cathode and agitating said alloy mechanically.By using the new process the three precious metals can be recovered simultaneously in one step with good efficiencies without any preliminary treating of the aluminate liquor and without using any auxiliary chemical.

Abstract: The invention relates to a new method of reducing the organic substance content of alum earth production cycle performed according to the Bayer technology. By the method of the invention the majority of the organic substances present in the circulating lye can be removed easily and with only slight losses in sodium content.According to the invention one proceeds so that soda present in the hydrate wash and/or in the soda salt solution is caustified with lime, the solution is evaporated to reach a total sodium oxide concentration of 200 to 400 g/l, the precipitated solid is separated and removed from the system, and the liquid is recycled.

Abstract: The invention relates to a novel process for the selective recovery of the sodium content of red mud originating from alumina plants. According to the process of the invention red mud or a slurry thereof is admixed with a ferric sulfate solution, the resulting suspension is stirred intensively for 0.5 to 1 hour at 15 to 85.degree. C, thereafter, if necessary, the pH of the suspension is adjusted to 4.4 to 4.6 and the solid substance is removed from the suspension.Using the process of the invention the sodium oxide content of red mud can be reduced to below 1.5%.