Green process for the preparation of pure iron

Patent metadata

Field	Value
Publication number	US-9879331-B2
Application number	US-201514839354-A
Country	US
Kind code	B2
Filing date	Aug 28, 2015
Priority date	Aug 29, 2014
Publication date	Jan 30, 2018
Grant date	Jan 30, 2018

Abstract

The present invention relates to an eco-friendly and single step process for the preparation of high purity iron by using hydrogen plasma in a suitable smelting reactor furnace. Reduction of iron oxide in excess of 99% can be achieved by reducing the iron ore in hydrogen plasma smelting system. The product quality is greatly improved as there is no instance of coke inclusion which otherwise would have carried carbon, sulphur, phosphorous, silica, etc. with it. In addition, this greatly diminishes carbon dioxide emission thereby making the process highly eco-friendly in nature. Apart from these, the process produces water as the only by-product. The process takes care of the green house effect with the non-involvement of gases like carbon dioxide, carbon monoxide during the operation. Thus, the present process is developed to produce high pure iron in a hydrogen plasma reactor without using carbon as reductant which thereby reduces the carbon dioxide emission drastically.

First claim

What is claimed is:

1. A green process for the preparation of pure iron from iron oxide without using carbon, wherein the said process comprises the steps of:
a) mixing iron ore fines with 1 to 15% by weight non-carbon additives to obtain iron oxide granules of size 0.2 to 6 mm as a feed material;
b) loading iron oxide granules as obtained in step a) in water cooled copper crucible with options for feeding iron oxide granules with varying feed rate during the course of operation through a feeder;
c) introducing Ar gas at flow rate in the range of 5-50 liters per minute (1 pm) into the reaction chamber for a period in the range of 1 to 2 minutes followed by establishing an electric arc to obtain molten iron ore; and
d) passing H 2 gas at flow rate in the range of 2-40 lpm to the reaction chamber with magnetic stirring for a period in the range of 30-180 min to obtain slag and pure iron.

2. The process according to the claim 1 , wherein iron oxide granules are fed into the reaction chamber at the feed rate in the range of 100-600 g/hr.

3. The process according to the claim 1 , wherein the non-carbon additive used is bentonite.

4. The process according to the claim 1 , wherein slag as obtained in step d) contains both magnetic fraction and non-magnetic fraction.

5. The process according to the claim 4 , wherein magnetic fraction is separated from the slag.

6. The process according to the claim 1 , wherein pure iron yield as obtained in step d) is in the range of 90-99% with purity in the range of 98.69 to 99.54% by weight.

7. The process according to the claim 1 , wherein no carbon dioxide is produced.

8. The process according to the claim 1 , wherein water is obtained as the only by-product in step d).

Assignees

• Council Scient Ind Res

Inventors

• Bhoi Byagyadhar
• Mishra Barada Kanta
• Paramguru Raja Kishore
• Sarangi Chinmaya Kumar
• Behera Pravas Ranjan
• Rajput Priyanka
• Mukherjee Partha Sarathi
• Priyadarshini Snigdha

Classifications

• C21B15/02

  Metallothermic processes, e.g. thermit reduction · CPC title

• C21B15/00

  Other processes for the manufacture of iron from iron compounds (by electrolysis C25C1/06) · CPC title

• C21B13/125

  By using plasma · CPC title

• C21C7/00 Primary

  Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 (treating molten metals during moulding B22D1/00, B22D27/00) · CPC title

• C21B13/0026 Primary

  introduction of iron oxide in the flame of a burner or a hot gas stream · CPC title