67 results about "Compounds of lead" patented technology

An outstandingly low environmental impact wet process recovers the lead content of an electrode slime and / or of lead minerals in the valuable form of high purity lead oxide or compound convertible to highly pure lead oxide by heat treatment in oven at relatively low temperature, perfectly suited for making active electrode pastes of new batteries or other uses. The process basically comprises the following treatments:a) suspending the impure lead containing material in an aqueous bath containing at least a lead oxide dissolving acid;b) reducing any insoluble lead dioxide to lead oxide by introducing in the suspension either hydrogen peroxide, a sulphite or sulphurous anhydride;c) converting all dissolved lead oxide to lead sulphate in the aqueous bath;d) obtaining a solution of lead sulphate obtained in an aqueous solution containing an acetate salt;e) precipitating and separating a purified lead compound in the form of either carbonate / oxycarbonate or of oxide / or hydroxide by adding to said acetate salt solution a carbonate salt or a hydroxide of the same cation of said acetate salt, respectively.Exemplary flow sheets according to several alternative embodiments and related processing plant diagrams are disclosed.

An all-wet process for reclaiming the lead content of impure electrode paste or slime from discarded lead batteries and / or lead minerals, in form of high purity lead compound, comprises a) suspending the impure lead containing material in a lead sulphate dissolving aqueous solution of a salt belonging to the group composed of the acetates of sodium, potassium and ammonium; b) adding to the suspension sulphuric acid in an amount sufficient to convert all lead oxides to lead sulphate soluble in the acetate salt solution and slowly adding to the suspension either hydrogen peroxide or a sulphite or bubbling sulphurous anhydride through it, in a measure adapted to reduce any lead dioxide to lead oxide converted eventually to soluble lead sulphate by the sulphuric acid; c) separating a limpid acetate salt solution containing dissolved lead sulphate from a solid phase residue including all undissolved compounds and impurities; d) adding to the separated solution of lead sulphate either carbonate or hydroxide of the same cation of the acetate salt of the lead sulphate dissolving solution for precipitating highly pure lead carbonate / oxycarbonate or lead oxide or hydroxide, respectively, while forming sulphate of the cation, soluble in the acetate salt solution; and e) separating the precipitated high purity lead compound from the acetate salt solution now containing also sulphate of the same cation of the acetate salt. The acetate salt solution containing also sulphate of the same cation of the acetate salt separated from the precipitated compound of lead is re-cycled to step a) and the content of sulphate of the same cation in the solution is maintained below saturation limit by continuously or periodically cooling at least a portion of the solution separated from the precipitated lead compound to cause selective crystallization of sulphate salt of the same cation of the acetate salt and removing it as a by-product. Optionally, the separated solid phase comprising insoluble compounds of lead and / or undissolved concretions of lead compounds is treated in hot concentrated hydroxide of the same cation of the selected acetate salt and converting these compounds of lead and / or undissolved concretions of lead compounds to soluble plumbites, and the separated lead containing alkaline liquor may be added to the limpid acetate solution for precipitating all reclaimable lead in form of high purity lead oxide or hydroxide.

Polymer fibers having a novel cross-sectional geometry are used as stationary phase materials for liquid chromatography separations. Fibers of 20 to 50 micrometer diameters have surface-channel structures extending their entire lengths. Bundles of fibers having this novel cross-sectional geometry are packed in columns. Different polymer compositions permit the “chemical tuning” of the separation process. Channeled fibers composed of polystyrene and polypropylene have been used to separate mixtures of polyaromatic hydrocarbons (PAHs), Pb-containing compounds and fatty acids. Use of channeled fibers allows a wide range of liquid flow rates with very low backing pressures. Applications in HPLC, cap-LC, prep-scale separations, analytical separations, single fiber separations, waste remediation / immobilization, extraction of selected organic molecules / ions from solution, purification of liquid streams (process waste, drinking water, pure solvents), selective extraction of cell matter and bacteria from growth media, and immobilization of cell matter and bacteria are envisioned.

The invention belongs to the field of inorganic nanomaterials, and involves a preparation method for sulfur compounds of lead nanomaterial by calixarene in a specific thermal control system solvent. Said method comprises placing lead salt and calixarene in a container, using toluene as solvent, stirring at 70-90DEG C for 0.8-1.5 hours to obtain a mixture, transferring the mixture into a reactor and adding sulfur source, adding toluene to 3 / 5-4 / 5 of the reactor volume and sealing, reacting at 150-200DEG C for 18-30 hours and cooling to room temperature, washing, separating, and drying to obtain the final product. The molar ratio of sulfur source to lead salt is 1 : 1, wherein the lead salt is one of lead nitrate and lead acetate and sulfur source is one of thiourea, sulfur powders, and selenium powders. The raw materials of this invention are easy to get and cheap. This invention also has the advantages of simple operation and equipment, high purity, convenient treatment, and being easy for industrialization. This invention provides a new method for preparing nanomaterials by controlled synthesis.

A cationic electrodeposition coating composition containing no heavy metal-based anticorrosive agents such as lead compounds, and which is capable of forming a coating film with a high corrosion resistance. The composition contains 0.5 to 20% by weight of a compound having an N-substitued benzoxazine ring represented by formula (1), relative to a resin solid matter, and an unsaturated hydrocarbon group-containing sulfide-modified epoxy resin as a base resin: wherein R is a hydrocarbon group having 1 to 8 carbon atoms.

The present invention aims to provide a piezoelectric composition which is free of lead based compounds and is represented by the following formula (1), (Bi<0.5x>Na<0.5x>Ba<0.7y+z>Ca<0.3y>) (Ti<x+y+0.8z>Hf<0.2z>) O<3> (1), wherein, x, y, z and a in formula (1) meets the following conditions, 0.70<=x<=0.90, 0.02<=y<=0.28, 0.02<=z<=0.28, 0.90<=a<=1.10 and x+y+z=1.

The invention relates to a preparation method for a large-area homogeneous organic-inorganic perovskite thin film and a product and application of the large-area homogeneous organic-inorganic perovskite thin film. The method comprises the following steps of 1) preparing lead-containing compound paste; 2) arranging a conductive substrate, silk-screen printing the lead-containing compound paste on the conductive substrate, and sintering the conductive substrate to obtain a uniform lead oxide thin film on the conductive substrate; and 3) respectively placing the lead oxide thin film in first steam and second steam for fumigation to prepare the uniform perovskite thin film. According to the method, a lead oxide precursor is prepared by a silk-screen printing method, and the homogeneous organic-inorganic perovskite thin film with high uniformity and controllable area is obtained by a series of simple fumigation chemical processing; and moreover, the process is simple, the repetitive rate is high, the cost is low, raw material is saved, and a large-area solar cell device with excellent and stable performance can be acquired.

The present invention is directed to an improved electroplating method, chemistry, and apparatus for selectively depositing tin / lead solder bumps and other structures at a high deposition rate pursuant to manufacturing a microelectronic device from a workpiece, such as a semiconductor wafer. An apparatus for plating solder on a microelectronic workpiece in accordance with one aspect of the present invention comprises a reactor chamber containing an electroplating solution having free ions of tin and lead for plating onto the workpiece. A chemical delivery system is used to deliver the electroplating solution to the reactor chamber at a high flow rate. A workpiece support is used that includes a contact assembly for providing electroplating power to a surface at a side of the workpiece that is to be plated. The contact contacts the workpiece at a large plurality of discrete contact points that isolated from exposure to the electroplating solution. An anode, preferably a consumable anode, is spaced from the workpiece support within the reaction chamber and is in contact with the electroplating solution. In accordance with one embodiment the electroplating solution comprises a concentration of a lead compound, a concentration of a tin compound, water and methane sulfonic acid.

A method for recovering valuable metals, such as lead, silver and gold from the residue of an electrolytic zinc process, wherein the residue from the zinc process is suspended and sulfidized for converting the lead and silver compounds into sulfidic form, and further flotated for forming a flotation concentrate that contains valuable metals, wherein the sulfidizing and flotation processes are controlled electrochemically, so that the content of the sulfide ions fed in the sulfidizing stage is adjusted by means of the redox potential to a level where the grain size of the created valuable metal sulfides is sufficient for flotating them, and that the redox potential of the flotation stage is adjusted to be within a range where the collector chemical is adhered to the mineral to be flotated, but the sulfides are not oxidized.

A piezoelectric ceramic composition that is based on a layered bismuth compound composed of Sr, Bi, Nb, oxygen, contains an additional monovalent metallic element. The piezoelectric ceramic composition has an elevated Curie point, is highly reliable at higher temperatures, that is, minimizes the reduction in the piezoelectric effect, and is useful as a material for piezoelectric ceramic devices that contain little or no lead or lead compounds. The layered bismuth compound contains not more than about 0.125 mol and more than 0 mol of the monovalent metallic element for 1 mol ofNb.

An igniting agent composition substantially free of a lead compound, characterized in that it comprises a metal power and one or more selected from the group consisting of nitrate salt, basic nitrate salt, a metal oxide and a basic carbonate salt; and an igniter using the igniting agent composition. The igniting agent composition shows no delay in ignition time and no reduction in igniting capability, as compared to conventional lead-containing composition.