Abstract: Chromium is selectively precipitated from waste solutions by means of benzoate ion. The resulting chromium benzoate complex is separated, washed and treated with either base or sulfuric acid to recover the benzoate and a chromium hydroxide product.

Abstract: Spent aqueous hexavalent chromium solutions containing trivalent chromium ions and extraneous metal ions are oxidized by placing said exhausted Cr.sup.+6 solution in the anode compartment of an electrolytic cell as the anolyte, said cell being separated into anode and cathode compartments by at least one cation selective membrane, said cathode compartment containing a catholyte, and impressing a direct current across the anode and cathode of said cell of a difference in potential sufficient to promote the oxidation of trivalent chromium in the solution in said anode compartment to hexavalent chromium while extraneous metal ions in the anolyte solution migrate through said membrane into the catholyte of said cathode compartment where copper ions are plated onto said cathode. The anode compartment consists of a removable and portable container consisting essentially of a framework having side members secured thereto, at least one of said anode members comprising a cation selective membrane.

Abstract: Instrumentation that can be lowered into an underground cavity to measure the dimensions of the cavity and also, as an added option, the ability to take photographs of the area of interest. The basic structure making up the preferred embodiment has a mounting frame with a television camera, a light beam assembly having two separate aligned light sources, and a mechanism to raise/lower the frame and also to tilt the light beam assembly. Above the ground is an appropriate readout unit which relates the angle of tilt for one of the light beam sources to a value of an electrical signal. To determine the distance from the aligned light source to the cavity surface, the light beams are superimposed upon one another to form a spot on the surface whose distance from the sources is to be measured. This spot is observed on the television camera and the signal magnitude (voltage) corresponding to the angle of tilt of the light source noted.

Abstract: Zirconium is selectively precipitated from aqueous solutions containing zirconium and uranium by treatment with a precipitant consisting of tartaric acid or a tartrate.

Abstract: A method of separating wrought and cast aluminum from a scrap mixture containing the two is disclosed. In this method, the scrap mixture is first heated to a temperature above the solidus temperature of the cast aluminum scrap. At this temperature, the scrap mixture is crushed thereby causing the cast aluminum to fragmentize into small pieces while merely causing flattening of the wrought aluminum. By using an appropriately sized screen, the cast aluminum fragments can then be separated from the wrought aluminum.

Abstract: A pressure vent for an explosion proof container. The vent allows a high flow rate of gases to pass from the container while arresting flames and cooling exiting hot gases therein. This precludes the build-up of high peak pressures inside the container. Structurally the vent has a protective cover mounted to the container by a knife hinge on one side and closed by imbedded magnets on the opposite side. In addition, the vent has multilayered material mounted in the same container opening near the interior of the container. A layer of porous stainless steel foam with multiple layers of stainless steel screen is used for this vital multilayered material. The optimum embodiment is obtained by preselecting a relationship between the free space volume inside the enclosed container, the number of layers in the prefilter section of the vent, and the cross sectional area of the vent.

Abstract: The gas monitor of the present invention is capable of simultaneously determining the concentrations of two members of a family of oxygen-containing gases present in an air sample. The monitor utilizes a four electrode potentiostat (58, 70, 12, 14) including two indicating electrodes (58, 70) mounting in a single electrochemical cell (8) and immersed in an aqueous electrolyte (10). The air sample containing the two family members is initially passed to the first indicating electrode (58), where electroreduction of the first family member produces a first electrical current directly proportional to the concentration of the first family member in the sample. Thereafter, the gas sample is passed through an oxidizing means (4) interconnected between the two indicating electrodes (58, 70), where all of the second family member is converted into the first family member.

Abstract: A system for automatically mapping the surface of a celestial body is presented. A satellite in a near polar sun-synchronous orbit about the body includes two or three linear sensing photo-detector arrays mounted transversely to the satellite heading. With two arrays, both are oriented at the same angle to the geometric vertical, with one aimed forward and the other aft along the apparent track of the satellite. With three arrays, the third array is oriented downward toward the geometric vertical. Two of the arrays are used to sense the body surface with the satellite velocity providing continuous imaging. With rugged terrain, one angled array and the vertical array sense linear strips of the body disposed parallel to the apparent path of the satellite. With relatively flat terrain the angled arrays are used. Data is acquired by sensing the same elemental areas of strips from a first position in space with a first array, and once the satellite has moved to a second position, with the second array.

Abstract: Chromium values are recovered from pulverized chromite ore by agitating and aerating an aqueous pulp of said pulverized chromite ore containing an amine collector at a pulp acidity less than 2.5; and recovering a chromite containing froth as a concentrate.

Abstract: A sonic agglomeration system wherein high sound intensity and resonance are maintained with a low power input. These functions are attained through the use of a chamber feed-horn design that promotes resonance and maximized the efficiency of sound transfer between a sound producing compression driver and a resonant chamber. A digital controller maintains efficient resonance in the chamber and an efficient agglomeration rate constant by making adjustments in the frequency, sound amplitude and nuclei injection rate of the system.

Abstract: Ferrochromium alloys are prepared by vacuum reduction of chromite concentrate by means of a carbonaceous reductant, followed by melting in the presence of slag-forming materials to produce the alloy and a separate slag phase. Preferably, CaO is employed as an ingredient in both the reduction step and the melting step.

Abstract: Metals are extracted from mixtures of oxides or silicates by reacting the mixture at elevated temperature with a gaseous chlorinating agent comprising a mixture of water vapor and hydrogen chloride to selectively chlorinate the desired metal or metals.

Abstract: A chromatography developing chamber for developing thin layer or paper chromatographic materials comprising an elongated sleeve closed at one end, open at the other end and having a peripheral wall therebetween, such as a cylindrical sample tube. A ledge projecting inwardly from a peripheral wall of the sleeve is positioned adjacent the closed end to provide a surface for supporting the chromatographic material in the chamber. A liquid elution solvent fills the chamber from the closed end to a level below the ledge such that the chromatographic material on the ledge is supported out of contact with the solvent during a first stage of developing. The ledge permits the material to be readily displaced therefrom to fall into the solvent during a second stage of developing. The material may be displaced from the ledge by vibration, as by tapping the chamber, or by magnetic means.

Abstract: Asymmetric reverse osmosis membranes are made from synthetic aromatic polyimides having a relatively high predominance of polar groups in the polymer backbone. A polar/non-polar group ratio of from 2:2 to 2:7 per imidized nitrogen link is required. Such membranes can be fabricated using conventional casting equipment by providing a solution of the polyimide in a good solvent and a poor solvent, the poor solvent being compatible with solution components at poor solvent/good solvent ratios of at least 1:1 up to about 7:1, casting a film of such solution, and partially evaporating the exposed surface of the cast film for 100.+-.30 seconds prior to gelation.

Abstract: A longwall mining machine comprises a rotatable cutting head having a configuration in the form of an equilateral triangle viewed along its axis of rotation and formed with a continuous auger along the outer surface of the head. Cutter bits are located on apexes of the auger. The cutting head is mounted on a boom adjacent the longwall and is geared to produce an eccentric Cardan motion to the head causing the cutter bits to follow a substantially square trajectory in a plane normal to the axis of rotation of the head. Production of coal dust is minimized by deep linear vertical and horizontal cuts extending downwardly from roof to floor. During rotation of the head, cut coal is augered outwardly from the longwall and dropped into a conveyor for removal to a collection area.

Abstract: Efficient dewatering of slimes is achieved by admixing the slimes with a flocculating agent, followed by mechanical manipulation to effect rapid removal of water and consolidation of solids. The required mechanical manipulation may be accomplished, e.g., by tumbling the mixture through a rotating cylindrical screen or by passing it across a vibrating screen.

Abstract: A packing media for column chromatography having multiple separation characteristics comprises adsorbent carbon powder particles adhered to the surfaces of individual particles of a molecular size exclusion gel polymer.

Abstract: A rotatable mounting block with a coal cutter bit which reduces the amount of wear to the bit. The cutter bit is fixed within the bore of a bit holder and moves in unison therewith within the mounting block. Positive rotation of the holder/bit is provided by a ratchet sleeve and pawl which interact with spiral slots on the lower extending end of the bit holder. The pawl prevents rotation of the ratchet sleeve in one direction (downward) so that the cutter bit will rotate during movement into the mounting block's bore as inwardly facing sleeve teeth are cammed in the slots of the bit holder. On the upward stroke of the bit/holder within the mounting block, the ratchet sleeve is free to rotate as a strong Belleville spring--also in the mounting block--forces them upward to the original position.

Abstract: A method for the in situ separation of viscous crude oil from a reservoir such as, oil sand, or tar sand is disclosed. Hot water is introduced to the top surface of the reservoir while steam is injected into the reservoir through drill holes. The hot water and steam may contain a surfactant. The bouyancy of the crude oil creates an artificial water drive which causes the water and oil to "flip-flop" so that the oil rises to the top of the reservoir and separates from the remainder of the reservoir material. If the overburden is deep, underground mining techniques may be used to reach the reservoir prior to applying the present method.

Abstract: An apparatus and method that gives very accurate measurements which allow one to determine the values of ionic activities of aqueous electrolyte solutions. To obtain these accurate measurements, moderately accurate measurements of vapor pressure differences between pure water (or a reference liquid) and the aqueous electrolytes is first obtained. A container with a known solution of nonvolatile electrolyte in water, i.e., a solution of known composition, is connected to one side of a differential pressure transducer, the other side of which is connected to a second container with a deionized double distilled water. Next, the gas in the containers and dissolved in liquids is evacuated by using a mechanical pump and the containers are immersed in a temperature controlled medium. At this point in time, the differential pressure transducer measures the difference in pressure.