Abstract: A physicochemical process for refining metal surfaces which includes the steps of introducing metallic objects to be refined and a solution capable of reacting with the metal to produce a softer phosphate or oxalate conversion coating on the metal surface into a finishing unit for agitation. Agitation is carried out to produce movement among the metallic objects for conversion of the metallic surface by the solution. The mechanical and chemical action achieves a reduction in the surface roughness of the metallic objects. A burnishing step is carried out by agitating the metallic objects with a burnishing liquid to remove the conversion coating and to achieve a specular finish. The burnishing liquid contains 0.01 to 1.5 weight percent of a phosphate compound and 0.002 to 0.2 weight percent of an organic slip agent and is used at a pH of 8.5 to 10.5. The low organic content of the burnishing liquid produces a waste stream having a low oxygen demand for waste treatment facilities.

Abstract: A composition for use in the physicochemical surface refinement of objects having surfaces of titanium, nickel, and alloys of each, normally in a vibratory mass finishing process, comprises the combination of sulfamic acid, ammonium bifluoride, and hydrogen peroxide. The maximum concentration of the peroxide is controlled to avoid inhibiting or arresting the reaction with the metal; maintaining a minimum concentration prevents excessive metal dissolution, pitting and other undesirable surface defects.

Abstract: A composition for use in the physicochemical surface refinement of objects having surfaces of titanium, nickel, and alloys of each, normally in a vibratory mass finishing process, comprises the combination of sulfamic acid, ammonium bifluoride, and hydrogen peroxide. The maximum concentration of the peroxide is controlled to avoid inhibiting or arresting the reaction with the metal; maintaining a minimum concentration prevents excessive metal dissolution, pitting and other undesirable surface defects.

Abstract: A composition for use in the vibratory mass finishing of magnetic stainless steel objects contains oxalic acid, sodium m-nitrobenzene sulfonate, and sodium thiocyanate, the latter two compounds being present in specified rations to one another. The preferred compositions include a hydroxyalkyl amine; for certain applications, they most desirably also include a poly(oxyethylene)-alkyl alcohol surfactant.

Abstract: A composition for use in the mass finishing of metal surfaces of objects, normally in a vibratory finishing process, utilizes the combination of oxalic acid, sodium nitrate, and hydrogen peroxide. The maximum concentration of the latter is limited to a value at which excessive dissolution of metal and pitting of the surface are avoided while, at the same time, cooperating with the nitrate to effect a substantial increase in the processing rate. Highly refined surfaces are achieved with the process in relatively short periods of time.

Abstract: Metal surfaces are refined, by the process of the invention, to high levels of smoothness in relatively short periods of time. A liquid substance is utilized to produce a conversion coating on the surface of the parts being treated, which are agitated, while being continuously wetted by the substance, in a mass finishing unit. Abrasive action causes the relatively soft coating to be removed from the high points of the surface, while leaving substantially intact the coating on the lower surface areas, with the coating being continuously repaired over metal exposed during operation. Fillage of the finishing unit container ensures efficient agitation and continuous oxygenation of the liquid substance, thereby maintaining a desirable rate of reaction and a high rate of surface leveling.

Abstract: An electroplating test cell comprises a tank having a housing supported within it, the housing being divided into an annular anode compartment and an inner cathode compartment. A cylindrical cathode support is mounted for rotation within the cathode compartment and is vertically adjustable therein to vary its position relative to electrolyte flowed within the compartment. The housing is supported near the bottom of the tank so that different levels of electrolyte may be maintained above the housing to provide varying liquid conditions ranging from a static pressure head to spray chamber plating. Rotation speed of the cathode support is variable to simulate different speeds of material movement through a plating bath.

Abstract: Precious metals such as gold and silver are recovered from aqueous cyanide solutions thereof by a stepwise process. The pH of the solution is, if necessary, initially adjusted to about 13 and thereafter is adjusted and maintained at 10 or above throughout the process. A "starter" carbonyl compound (e.g., formaldehyde or dextrose) which reacts with free cyanide ions is dissolved in the solution. Following this, an "accelerator" (e.g., hydrogen peroxide or a persulfate) is added and the solution is heated to aid in conversion of free cyanide ions to other chemical species. Finally, a "clarifier" (e.g., hydrazine or a hydrosulfite) is added and the elevated temperature is maintained for at least a brief period after the addition. The solution is then cooled and the elemental precious metal particles formed are allowed to settle and are separated from the supernatant solution.

Abstract: A process for making high purity alkali produced is sulfite substantially free from chloride ions includes the step of admixing gold chloride solution with magnesium oxide at an alkaline pH to form magnesium aurate which is recoverable as a coating upon the magnesium oxide precipitate. The magnesium aurate is thereafter admixed with a solution of alkali metal sulfite at an alkaline pH to produce alkali metal gold sulfite and a precipitate of magnexium oxide.When the alkali metal gold sulfite being produces ia a potassium gold sulfite, the process desirably includes the step of admixing the potassium gold sulfite with a sulfamic acid compound to provide stability. The magnesium aurate precipitate is desirably rinsed to remove chloride ion contamination.

Abstract: A dry powder composition for stripping gold and silver contains 78.0-95.0 percent of a soluble cyanide compound, 0.01-5.0 percent of a soluble lithium compound, 0.01-0.5 percent of a soluble lead or bismuth compound as an auxiliary agent, and 5.0-22.0 percent of a water soluble ring-substituted nitrobenzene acid compound. The nitrobenzene acid compounds are selected from the group consisting of the alkali metal and ammonium salts of methyl-nitrobenzoic acid, chloro-nitrobenzoic acid and amino nitrobenzoic acid and of chloro-nitrobenzenesulfonamides. In using the composition, 7.5-60.0 grams per liter of the dry powder composition is dissolved inwater and the resultant aqueous solution is maintained at a temperature of 18.degree.-55.degree. Centigrade. The solution may be replenished as the stripping rate decreases by addition of further amounts of the dry powder composition.

Abstract: A composition for use in the vibratory mass finishing of magnetic stainless steel objects contains oxalic acid, sodium m-nitrobenzene sulfonate, and sodium thiocyanate, the latter two compounds being present in specified rations to one another. The preferred compositions include a hydroxyalkyl amine; for certain applications, they most desirably also include a poly(oxyethylene)alkyl alcohol surfactant.