Abstract: In dual temperature systems utilizing different fluid materials in liquid and gas phases separable from each other (for example H.sub.2 O and H.sub.2 S), the phases are contacted with each other at a relatively hot temperature. Herein combinations of method and means are provided by which the gas is conditioned by raising its temperature and humidity principally by heat derived from the cooling and dehumidification of said gas. Special provisions are made in the combinations for transferring said heat and for the conditioning of the gas with high efficiency; and for economically controlling the temperature of the condensate resulting from the dehumidification of the gas to adapt it for particular uses in the system. Method and means are provided for such liquid gas contacting systems for efficiently stripping or separating dissolved gas from the effluent liquid and returning one of the so separated materials to the system.

Abstract: Improvements in apparatus for zone refining polycrystalline semiconductor rods to produce monocrystalline semiconductor rods are disclosed. In the apparatus, an inductive heating chamber is employed which has a longitudinal dimension independent of the length of the polycrystalline semiconductor rod to be processed. The longitudinal dimension of the induction heating chamber is limited only by considerations of the space required for the RF induction heating coil and related apparatus which must be mounted within the chamber, the viewing space required for the operator to observe the zone refining process, and the heating effect on the structures above and below the chamber. First and second gas tight bellows are provided which, respectively, surround the rod holder and the seed holder.

Abstract: Soft hexagonal boron nitride crystals of 200-600 microns platelet size are produced from crystals of less than fifty microns particle size by mixing the small crystals with Li.sub.3 N, simultaneously heating and pressurizing said mixture to a temperature and pressure in a restricted region of the graphitic (hexagonal) boron nitride (GBN) stable region of the pressure-temperature (P-T) phase diagram of boron nitride, cooling and depressurizing said mixture, and separating off the water soluble material present in the mixture to leave a residue of large crystals of boron nitride.

Abstract: Single crystals of neodymium pentaphosphate greater than one centimeter in size and of high purity and quality are grown from polyphosphoric acid solutions using the combination of a dilute solution, seeding, growth temperatures of 500.degree. to 650.degree. C, and a double crucible configuration.

Abstract: Relates to a method for producing a product comprising crystalline silicon on a sodium thallium type substrate by application of silicon atoms gradually to that substrate whereby oriented overgrowth occurs and also to the product produced by said method. The product is useful in semiconductor and solar cell applications.

Abstract: A liquid phase, which comprises either at least one of the constituents of the compound or alloy of which the crystal is to be prepared, or a foreign material, is fed continuously at its surface with the other constituent or constituents of this compound or alloy (or with all the constituents when the liquid phase comprises a foreign material). This liquid phase is subjected to two successive temperature gradients the first of which is slight and the second steep, so that the constituents are transported through the liquid phase and so that the crystallization of the compound or alloy takes place at the level of the second gradient. The liquid phase and the temperature gradients are displaced with respect to each other at a speed determined such that the composition of the liquid phase does not change and such that the crystallization always takes place at the same temperature.

Abstract: The seed to tail oxygen concentration gradient in silicon crystals, which are drawn from a silicon melt contained in a silica vessel according to the Czochralski process, is controlled by a process employing stop-go crucible rotation to provide fluid shearing at the melt-crucible interface.

Abstract: An annular crucible for containing molten, inorganic crystalline material in an apparatus for growing a plurality of substantially monocrystalline articles including a plurality of spaced forming members disposed in a ring-like arrangement within the crucible, and a pair of annular resistance heating elements concentric with the annular crucible, one element proximate the crucible inner wall and one element proximate the crucible outer wall. In combination with the annular crucible, a thin, ring-shaped resistance heating element substantially conforming in outside and inside diameters to those of the crucible and being disposed at a predetermined distance above the crucible, the ring element having apertures for passing the monocrystalline articles and having means for an independently controllable heat output.

Abstract: A method and horizontal furnace for vapor phase growth of HgI.sub.2 crystals which utilizes controlled axial and radial airflow to maintain the desired temperature gradients. The ampoule containing the source material is rotated while axial and radial air tubes are moved in opposite directions during crystal growth to maintain a desired distance and associated temperature gradient with respect to the growing crystal, whereby the crystal interface can advance in all directions, i.e., radial and axial according to the crystallographic structure of the crystal. Crystals grown by this method are particularly applicable for use as room-temperature nuclear radiation detectors.

Abstract: Inorganic macrocrystals are grown free of occluded gases in a quiescent melt in a Bridgmann, Stockbarger, or similar furnace by melting down the crystal feed stock under a reduced atmosphere composed primarily of a low molecular weight gas such as hydrogen, helium or neon having the ability to diffuse through the melt at a greater rate than that of nitrogen. The gas can also include a minor amount of one or more active scavenger gases. During crystal growth, the gas atmosphere over the melt is altered by replacing the low molecular weight gas with an inert gas having a lower solubility in the melt than that of the low molecular weight gas or by increasing the pressure of the low molecular weight gas at a specified point in the growth process to significantly increase the concentration needed to form bubbles in the melt and to retard evaporation of the melt.

Abstract: This invention relates to a method of growing a single quartz crystal stone. In particular, a method for hydrothermally growing a quartz stone from a quartz seed is disclosed. A substantially stress-free quartz stone is grown in an autoclave by clamping a quartz crystal seed plate in a clip so as to permit substantially unobstructed growth of the stone in the plane of the seed plate, and growing at least a portion of the stone through at least one aperture formed in the clip.

Abstract: Apparatus for introducing a preselected quantity of soluble fertilizer into a water stream in a fully dissolved state is disclosed. The apparatus includes a tank and a porous receptacle disposed within the tank and adapted to receive the fertilizer. The bottom of the receptacle is spaced upwardly from the bottom of the tank to provide a plenum volume beneath the receptacle at the bottom of the tank. Water is dispensed in a dispersed state onto the soluble fertilizer in the porous receptacle. The water drains through the fertilizer to dissolve it and the water containing the dissolved fertilizer passes through the porous receptacle and is collected in the plenum volume at the bottom of the tank. A float is provided for sensing the level of water in the plenum volume. A valve is connected to the float and interrupts the dispensing of water to the fertilizer when the level of water approaches the bottom of the porous receptacle.

Abstract: A process for preparing from aqueous NaCl brine containing appreciable quantities of dissolved calcium sulfate high purity dendritic salt, characterized by an exceptionally low calcium sulfate content. The process is carried out by a "feed and bleed" procedure comprising admixing an alkali metal polyphosphate with said brine to increase the supersaturation of calcium sulfate therein, feeding the brine containing this additive into an evaporating and crystallizing chamber, evaporating the brine at an elevated temperature and reduced pressure to cause crystallization of pure salt and concomitantly bleeding brine from the chamber, the rate of feed of the brine to the chamber and the rate of bleed of brine from the chamber being such as to maintain the calcium sulfate in the dissolved state and prevent its precipitation with the salt.

Abstract: Method for producing massive unicrystalline R-plane alpha alumina of circular cross-section from an alumina melt by controlled rotation of the seed rod upon which the alpha alumina is solidified and crystallized.

Abstract: A method of producing citrine crystals comprising the step of growing citrine crystals under hydrothermal conditions by the temperature difference method in a high-pressure autoclave on crystalline quartz seeding plates oriented in parallel with the pinacoid crystallographic plane {0001} or with planes inclined at an angle within the range of up to 20.degree. with respect to said pinacoid plane using a charge comprising crystalline quartz and aqueous solutions of potassium carbonate with a concentration of from 5-10 wt.%. Said solutions contain iron introduced in the autoclave in the form of metallic iron in an amount of from 2-20 g per lit. of the solution, as well as nitrites or nitrates of alkali metals or potassium permanganate which are introduced in the autoclave in an amount of from 1-20 g per lit. of the solution. The above-described method of growing citrine crystals is carried out at a crystallization temperature of from 300.degree.-345.degree. C, under a pressure of from 300-1500 kg/cm.sup.

Abstract: A method of growing multiple monocrystalline layers from melts comprising growing a first monocrystalline layer from the first melt, and growing a second monocrystalline layer on the first monocrystalline layer from the second melt by successively contacting the first monocrystalline layer with the second melt during the growth of the first monocrystalline layer.

Abstract: A process for producing amethyst crystals involving growing of colorless quartz crystals by a hydrothermal method of a temperature drop in a high-pressure autoclave on crystalline quartz seed plates oriented parallel to the crystallographic planes of the major {1011} and minor {1101} rhombohedrons using crystalline quartz as a charge. Said growing is effected from aqueous solutions of potassium carbonate or potassium hydroxide having a concentration ranging from 4 to 7 wt.% and containing iron introduced into the autoclave in the form of metallic iron or in the form of its oxydic or hydroxydic compounds in an amount ranging from 5 to 30 g/l of the solution. The growing process is effected at a crystallization temperature within the range of from 300.degree. to 500.degree. C. under a pressure ranging from 200 to 1,700 kg/cm.sup.2 and a crystal growth rate of from 0.05 to 0.5 mm/day.

Abstract: A method and apparatus for the production of coke from coal by a dry distillation operation wherein the coking plant is provided with a computer unit that receives signals from the coal leveling mechanism, the door mechanism, the quenching car mechanism, and a signal value for the time required to achieve the coking of the coal. The computer prevents the opening of any given coking chamber until the minimum coking time has lapsed and the opening of the chamber and discharging and quenching of the coke is correlated to the actual operating conditions rushing at that time. If desired, the charging and emptying operations may be carried out on a completely automatic basis.

Abstract: In a hydrothermal process for manufacturing crystals of metal carbonates, including single crystals of lead carbonate of the cerussite crystalline form, the nutrient material consists of a carbonate or basic carbonate of the said metal, the solvent medium consists of a 0.5 to 5.0 molar aqueous solution of an alkali metal bicarbonate, and the heating is carried out in an autoclave under controlled temperature conditions such that the exterior of the autoclave wall adjacent to the nutrient and the solvent medium in the vicinity thereof is maintained at 200.degree. C to 400.degree. C, and that the exterior of the autoclave wall adjacent to the region of the solvent medium remote from the nutrient is maintained at 170.degree. C to 315.degree. C and at a temperature from 5.degree. C to 150.degree.

Abstract: Process for producing high bulk density sodium carbonate monohydrate crystals from sodium carbonate solutions wherein the sodium carbonate monohydrate is crystallized in the presence of at least 30 parts per million soluble aluminum ions.