US1425661A

US1425661A - Process of manufacturing zinc dust

Info

Publication number: US1425661A
Application number: US340928A
Authority: US
Inventors: Kato Teisuke
Original assignee: Individual
Current assignee: Individual
Priority date: 1919-11-26
Filing date: 1919-11-26
Publication date: 1922-08-15
Anticipated expiration: 1939-08-15

Description

T. KATO.

PROCESSDF MANUFACTURING ZINC DUST. APPLICATION FILED NOV-26.1919.

ITTY

' Patented Aug. 15, 1922.

TEISUKE KATO, OF I-IYOGO KEN, JAPAN.

PROCESS OF MANI IFACTURING ZINC DUST.

Specification of Letters Patent.

Application filed November 26, 1919. Serial No. 340,928.

To all whom it may concern:

Be it known that I, TEISUKE KATo, subject of Japan, residing at No. 2187/1, Maura, Iejima Mura, Shikama Gun, Hyogo Ken, Japan, have invented new and useful Improvements in a Process of Manufacturing Zinc Dust, of which the following is a specification.

This invention relates to a process of manufacturing zinc dust consisting in converting metallic zinc or. ores or other materials containing metallic zinc or zinc oxide, into zinc vapor by heating the material together with a reducing agent by fuel or electricity in afurnace or retort so constructed that it is not exposed to the atmospheric air; diluting the said zinc vapor with a non-oxidizing gas, and settling very fine zinc dust by suddenly cooling the said zinc vapor. The object of this invention is to manufacture very fine zinc dust in large quantities containing maximum proportions of metallic zinc.

The accompanying drawings show an example of apparatus for carrying my invention into practice, in which Fig. l is a vertical section, side view;

Fig. 2, a vertical section, front view, and

Fig. 3, a cross section, plan view.

The same reference numbers refer to the same or corresponding parts throughout all the figures.

Zinc dust is generally obtained as a byproduct when distilling zincv in retorts; but the density of the zinc vapor in this case be ing comparatively great and the temperature of the condenser being comparatively high, it is possible to obtain only a limited quantity of zinc dust. Moreover, zinc dust thus obtained is very coarse, part of it oxidized, and the metallic zinc contained therein is comparatively small in quantity.

The present invention removes the above drawbacks by diluting zinc vapor with a nonoxidizing gas and cooling it quickly, thus making it possible to manufacture commercially any desiredamount of zinc dust.

The following is an example of carrying the invention into practice. 1

In the accompanying drawings 1 is a fire grate; 2, a chute for charging the furnace with coal; 3 are retorts; and 4; are passages for gaseous zinc volatilized in the retorts, the said passages being cooled by water jackets. Each retort is provided at one end with a duct 6 for the introduction of a gas into the retort, and also with a port located approximately at 7 to feed zinc in the form of a rod or the like to replace volatilized zinc, it being understood that any suitable form of valve may be provided for con trolling the dust 6 and a suitable stopper may also be provided for the port 7; 5 are settling chambers made of thin plate, having internal partitions and cooled by the air; 8 are smoke flues, and 9 is an air passage provided between the smoke flues and opening into the furnace at 10, to heat the air with the heat of the smoke and thus to cause complete combustion of the gas which rises from the grate, thereby to give a greater length to the grate flame. v

To work this apparatus, the retorts are first heated until they become red. The retorts are then fed with a suitable amount of zinc after which the feeding ports are closed, and the temperature gradually raised.- lVhen the temperature in the interior of the furnace'reaches 1000 to 1200 C., the zinc contained in the retorts will begin to volatilize. Then, the gas ducts are opened and a non-oxidizing gas, such as carbon monoxide, nitrogen, acetylene, pure coal 1 gas or the like, introduce into the retorts so as to dilute the gaseous Zinc to a considerable extent. The gaseous zinc thus diluted is led through the cooled passages 4 to the settling chambers 5, where it entirely settles as a very fine powder of metallic zinc. The proportion of the nonoxidizing gas used for diluting the gaseous zinc is preferably 256 cubic feet at ordinary temperature for 8 pounds of zinc.

It is to be understood that it is not essential to use the identical apparatus shown in the accompanying drawings. For heating purpose, electricity may be used, and the settling chamber may be cooled by a water jacket, or the settling of the zinc may be accelerated by the provision of a cooling pipe. v

In this invention, instead of metallic zinc, zinc ore oxidized by roasting, or any other material containing zinc oxide, may be Patented Aug. 15, 1922.

charged into the retorts together with a reducing agent and zinc may be volatilized as it is reduced.

Claim: 7 A process of manufacturing zinc dust which consists in volatilizing by heat metallic zinc in a retort from which atmospheric air is excluded; diluting the zinc thus