Method for high-purity tin recovery and hydrogen production using methane reduction

Abstract

The present invention relates to a method of using a methane gas to recover tin with high purity and to produce hydrogen at once, and the method uses the methane reduction technique that combines the two different processes of tin recovery and hydrogen production, thereby recovering tin with high purity from a methane gas and a tin oxide according to the methane reduction technique stably without emission of environmental pollutants, such as carbon dioxide, sulfur dioxide, nitrogen oxide, etc., and also producing hydrogen available as a new energy resource. Further, the present invention enables the recycling of waste materials containing tin oxides generated in all kinds of industries to prevent environmental contaminations and to offer solutions to the stable recovery of expensive tin with high purity and the dramatic reduction of hydrogen production costs at once, increasing economical efficiency and thus contributing to the efficient use of resources.

Description

TECHNICAL FIELD[0001]The present invention relates to a method for high-purity tin recovery and hydrogen production using methane reduction, and more particularly to a method of conducting a dry reduction of tin oxide using methane gas as a reducing agent not only to recover high-purity tin but also to produce hydrogen as a byproduct from the methane gas used as a reducing agent without production of environmental pollutants.BACKGROUND ART[0002]Tin is a carbon-group chemical element with symbol Sn in group 14 and period 5 of the periodic table. It is a post-transition metal that is highly malleable, ductile and corrosion-resistant and ready to melt and hence extensively used with its high castability. Particularly, it plays an important role as a Pb-free solder in the electronic components and materials industry and is extensively used as a core material in the manufacture of LED TVs, alloy materials, plating materials, electric contact materials for electric and electronic products...

AI Technical Summary

Benefits of technology

The present invention is a new method that combines two different processes, namely the recovery of tin from methane gas and the production of hydrogen. This method allows for a stable recovery of tin with high purity from methane gas and tin oxide without emitting environmental pollutants such as carbon dioxide, sulfur dioxide, and nitrogen oxide. Additionally, this invention produces hydrogen as a new energy resource, which can be utilized in various industries. This method also enables recycling of waste materials containing tin oxides to prevent environmental contamination and provide a solution to the stable recovery of expensive tin with high purity and the reduction of hydrogen production costs. Overall, this invention offers economical efficiency and efficient use of resources.

Problems solved by technology

This results in an imbalance between supply and demand, a high rise of price and high price fluctuations in the international tin markets.

The methods of recovering tin from tin oxides using dry reduction or wet reduction are deployed on a commercial scale, but mostly involving the recovery of tin from waste solders or scraps or sludge having a relatively high tin content, and results in the emission of slags, chemical waste water, and carbon dioxide in large quantity.

Unavoidably, this method also involves the emission of slags and carbon dioxide in large quantity to cause environmental contaminations.

But, the method is so problematic as it has high cost of process, spending long time for purification and using a large amount of reagents, as well as generating chemical wastewater in large quantity.

Yet, the conventional methods have more serious problems, such as low thermal efficiency, poor economical efficiency and low expandability, than the above-mentioned ones with the dry reduction or wet reduction method regarding emission of pollutants and formation of waste residues.

The reforming method of using steam as a catalyst involves a considerably complicated process and results in emission of a byproduct, carbon dioxide, in addition to the desired product, hydrogen.

In the case of using a catalyst, the reaction of the reforming method is endothermic due to its characteristic as it takes place only at high temperatures of about 700 to 1,200° C., so the method requires the use of a specialized reforming furnace and incurs additional expenses in association with the reduced life span and durability of the catalyst at high temperatures.

The method using the partial oxidation of hydrocarbons also requires the use of a specialized furnace for partial oxidation and creates a lot of shoot, which necessarily adds a separate process of disposal and leads to deterioration of the catalyst.

The high-temperature pyrolysis using plasma is a process not causing the emission of carbon dioxide, but energy intensive in the pyrolysis of methane, increasing the hydrogen production cost.

Images