Abstract: A process for in situ anaerobic bioremediation of contaminated earth media and solid waste media, including mining and chemical plant wastes, is shown. The process includes creating an emulsion of organic liquid dispersed in water, followed by infiltrating the emulsion into the media. Water, as the continuous emulsion phase, provides low viscosity and media wetting, favorable to infiltration. The emulsion disengages inside the media leaving dispersed organic nutrient attached to the media where it is accessible for microbial redox reactions, causing anaerobic conditions. Bioremediation includes sulfate reduction and precipitation of metal sulfides, and many other contaminant altering reactions achievable under anaerobic conditions. Components of the organic liquid are selected to enhance microbial activity and media adhesion. Contaminated groundwater and surface water, such as acid mine drainage, can be treated as they flow through a saturated media bed after the emulsion has been introduced into the media.

Abstract: A process for in situ anaerobic bioremediation of contaminated earth media and solid waste media, including mining and chemical plan wastes, is shown. The process includes creating an emulsion of organic liquid dispersed in water, followed by infiltrating the emulsion into the media. Water, as the continuous emulsion phase, provides low viscosity and media wetting, favorable to infiltration. The emulsion disengages inside the media leaving dispersed organic nutrient attached to the media where it is accessible for microbial redox reactions, causing anaerobic conditions. Bioremediation includes sulfate reduction and precipitation of metal sulfides, and many other contaminant altering reactions achievable under anaerobic conditions. Components of the organic liquid are selected to enhance microbial activity and media adhesion. Contaminated groundwater and surface water, such as acid mine drainage, can be treated as they flow through a saturated media bed after the emulsion has been introduced into the media.

Abstract: Methods are disclosed for treating smelter flue dust and other smelter by-products so as to recover non-ferrous metals therefrom and convert arsenic and sulfur in the flue dust into non-leachable compounds. The methods allow the flue dust and other smelter by-products such as smelter sludges to be disposed of in a natural environment without subsequent leaching of heavy metals, sulfur, and arsenic. The smelter by-products are mixed with hydrated lie, formed into agglomerates, and roasted at an optimal temperature of about 650.degree. C. to form oxidized arsenic and sulfur which react with the lime in the agglomerates to form non-leachable compounds. The roasted agglomerates are contacted with a basic lixiviant comprising dissolved ammonia and an ammonium salt to dissolve non-ferrous metals such as copper from the roasted agglomerates. Used lixiviant can be boiled to precipitate the non-ferrous metals dissolved therein and vaporize the ammonia, thereby regenerating the lixiviant.

Abstract: A closed-cover hot cyclone reactor is used to melt and partially reduce particulate iron or ferro-alloy ores fed to it in a stream. Tangential streams of fuel gas or, preferably, producer gas supplied by an associated bath smelter, interact with the spiralling particles as they pass through the reactor. The molten metal travels downwardly along the reactor walls and can be discharged by gravity onto the receiving bath. The system eliminates the need for pelletizing ore and coking coal in smelting of iron products.

Abstract: A process for producing salt free titanium powder by reacting zinc and a titanium halide in the presence of a reducing agent to form a solid zinc titanium product. Titanium halide vapor is introduced into a liquid alloy of zinc and the reducing agent at a temperature between 650.degree.-907.degree. C. The titanium halide is introduced beyond the titanium solubility limit in zinc to precipitate a zinc titanium intermetallic compound and also produce a liquid halide salt. The intermetallic compound forms and accumulates at an interface between the salt and liquid alloy. The compound is periodically removed from the interface, crushed into a powder, and the zinc is evaporatively separated from the titanium to produce pure titanium powder. The process preferably occurs above the peritectic decomposition temperature of Zn.sub.3 Ti, and most preferably above the peritectic decomposition temperature of Zn.sub.2 Ti, to maximize the titanium content of the resulting product.

Abstract: Disclosed are coated metal articles having protective coatings which are applied to substrate metals by coating the metal surface, e.g. by dipping the substrate metal in a molten alloy of the coating metals, and then exposing the coating at an elevated temperature to an atmosphere containing a reactive gaseous species which forms an oxide, a nitride, a carbide, a boride or a silicide. The coating material is a mixture of the metals M.sub.1 and M.sub.2, M.sub.1 being zirconium and/or titanium, which forms a stable oxide, nitride, carbide, boride or silicide under the prevailing conditions. The metal M.sub.2 does not form a stable oxide, nitride, carbide, boride or silicide. M.sub.2 serves to bond the oxide, etc. of M.sub.1 to the substrate metal. Mixtures of M.sub.1 and/or M.sub.2 metals may be employed. Eutectic alloys of M.sub.1 and M.sub.2 which melt substantially lower than the melting point of the substrate metal are preferred.

Abstract: Protective coatings are applied to substrate metals by coating the metal surface, e.g. by dipping the substrate metal in a molten alloy of the coating metals, and then exposing the coating at an elevated temperature to an atmosphere containing a reactive gaseous species which forms an oxide, a nitride, a carbide, a boride or a silicide. The coating material is a mixture of the metals M.sub.1 and M.sub.2, M.sub.1 being zirconium and/or titanium, which forms a stable oxide, nitride, carbide, boride or silicide under the prevailing conditions. The metal M.sub.2 does not form a stable oxide, nitride, carbide, boride or silicide. M.sub.2 serves to bond the oxide, etc. of M.sub.1 to the substrate metal. Mixtures of M.sub.1 and/or M.sub.2 metals may be employed. This method is much easier to carry out than prior methods and forms superior coatings. Eutectic alloys of M.sub.1 and M.sub.2 which melt substantially lower than the melting point of the substrate metal are preferred.

Abstract: A process for producing titanium metal in finely-divided particulate form, by forming a liquid mixture of titanium and zinc, fracturing and solidifying the liquid mixture and evaporating zinc from the resulting finely-divided particles to produce finely divided particulate titanium. Titanium alloys may be produced by adding an alloying metal or metals to the liquid titanium-zinc mixture prior to fracturing, solidification and zinc evaporation. The liquid mixture of titanium and zinc may be produced by reaction of a reducing metal in a liquid mixture of zinc and reducing metal with titanium tetrachloride to produce reducing metal chloride and a liquid mixture of titanium and zinc. The reducing metal chloride is separated from the mixture of titanium and zinc. The alloying metal may be added to the liquid mixture of titanium and zinc by reacting alloying metal chlorides with the reducing metals in the liquid mixture of zinc and reducing metal.

Abstract: In a process for the production of alumina from aluminous raw material, an ammonoalunite intermediate is formed. The raw material is preferably a clay which is leached with sulfuric acid to form an aluminous solution which is separated from the solid materials. After any required extraction of iron, such as by liquid ion exchange, the solution is subjected to elevated temperatures and pressures in the presence of ammonium ions to form ammonoalunite which is recovered as a precipitate. The liquor is recycled to leach the clay, while the ammonoalunite is thermally decomposed to alumina. Gases liberated during decomposition are scrubbed with recycled liquor to form clay leach liquor. The alumina may be purified by washing with sulfuric acid to obtain a purity suitable for aluminum electrolysis.

Abstract: An inexpensive photovoltaic device made using particulate silicon is described. Silicon particles of a particular type having a size range of from 300 to 1000 micrometers are sintered to a metallic substrate to form an ohmic contact therebetween. The particles and the substrate are provided with an insulating layer except for the top surfaces of the silicon particles, to which a layer of the opposite type is applied to form p-n junctions in the particles. A second electrode is then applied either directly or, preferably, via a first application of a transparent conductive coating. The device is then, preferably, covered with a light transparent member to provide a hermetic seal.

Abstract: Process for applying a protective coating to a metal substrate which provides a thermal barrier and a barrier against oxidation of the substrate. The coating material is a mixture of two metals M.sub.1 and M.sub.2, e.g., cerium (M.sub.1) and cobalt (M.sub.2), one of which when exposed to an atmosphere containing a low partial pressure of oxygen and at a high temperature forms a stable oxide, the other of which does not form a stable oxide under such conditions. A coating consisting of such a metal alloy or mixture is subjected to such conditions to produce an outer oxide layer of metal M.sub.1 and an inner metal layer of M.sub.2 alloyed with one or more components of the substrate. The oxide layer provides thermal and oxidation protection and the inner layer bonds the coating to the substrate.

Abstract: Silicon (Si) is cast into thin shapes within a flat-bottomed graphite crucible by providing a melt of molten Si along with a relatively small amount of a molten salt, preferably NaF. The Si in the resulting melt forms a spherical pool which sinks into and is wetted by the molten salt. Under these conditions the Si will not react with any graphite to form SiC. The melt in the crucible is pressed to the desired thinness with a graphite tool at which point the tool is held until the mass in the crucible has been cooled to temperatures below the Si melting point, at which point the Si shape can be removed.