GB2354514A

GB2354514A - Stabilizing ferrous sulphate

Info

Publication number: GB2354514A
Application number: GB9923752A
Authority: GB
Inventors: Hossein Salar Amoli; Faraj Mohana Zadeh
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-09-27
Filing date: 1999-09-27
Publication date: 2001-03-28
Anticipated expiration: 2019-09-27
Also published as: GB9923752D0; GB2354514B

Abstract

Ferrous sulphate is stabilized against oxidation by the addition of sodium hydrogen phosphate (Na<SB>2</SB>HPO<SB>4</SB>). The ferrous sulphate is prepared by the reaction of metallic iron with dilute sulphuric acid and the sodium hydrogen phosphate may be added near to the end of the reaction to give a ratio of phosphate to sulphate in the range of 1:99 to 0.7:99.3.

Description

2354514

Background of the invention This invention relates to a process for the stabilizing of ferrous sulphate.

Sufficient iron in the diet of humans and animals is essential for tissue growth. In addition, iron is necessary for the biosynthesis of ironsulphur proteins such as rubedoxin. Although a sufficient amount of iron can usually be found in the diet, the level of absorption of this element from food is generally low, therefor, the supply of iron can become critial. Iron deficiency anemia is commonly encountered in pregnant women and may also be a problem in the newborn especially in animal cases. The supply of iron for human, animal and plant is possible by using ferrous sulphate. Conventionally ferrous sulphate is available as heptahydrate FeS04.7H20.

It is odorless green crystals or granular which is soluble in water and glycol but insoluble in alcohol, acetone and methyl acetate. On being heated to 60400C three mol of water is driven off to form FeS04.41120- In the absence of air at ca 3000C ferrous sulphate monohydrate, a white powder is formed. Ferrous sulphate has a major disadventagc, however that they are sensitive to oxidation, especially in moist air and aqueous environments. In moist air, the surface of the crystals of FeS04 - X H20 becomes converted with brownish basic ferric sulphate Fe2(SO4)3- X1120. The rate of oxidation by air increases in alkaline solution and rasing the temperature and humidity.

This can be hindered initially by protectively coating ferrous sulphate in tablet form. However, when they dissolve in the gut, oxidation still occurs to give insoluble ferric sulphate which is assumed to be less soluble in the pH range 4 4 than ferrous sulphate, so in the case of oxidation enough iron is not absorbed.

Based on this invention it is possible to prevent oxidation of ferrous sulphate even in moist air by using sodium hydrogenphosphate ( Na2HP04)Application Ferrous sulphate has few main areas of application a) on the growth and nutrient uptake of plant b) feed additive c) increasing haemoglobin regeneration efficiency.

Description Ferrous sulphate is produced by dissolving iron in dilute sulphuric acid.

The process of the invention involves the reaction of sulphuric acid with a second reactant which is metallic iron. When the reaction is in progress adding an amount of sodium hydrogenphosphate to the reactor such that the ratio of Na2HP04 to the ferrous sulphate is in the range of 1:99 to o.7:99.3.

An example of the invention will now be given: The apparatus used comprised a rotating drum reactor with a general capacity of ca 1000kg. An amount of 500L diluted sulphuric acid (4M) was added into the rotating drum reactor which rotated at a speed of about 4rpm. Thereafter, an amount of 112kg of metallic iron was added to the rotating reactor over a period of 2hrs. At the end 2.8kg sodium hydrogenphosphate added and the reactor was allowed to rotate for further 20min. The crystalline ferrous sulphate heptahydrate was filtered, discharged on a convey or belt and dried by means of a fan. The greenish colour of product is stable even at very moist air.

The process of the invention has two major adventage. Firstly, provides an inexpensive route to the manufacture for stabilizing the ferrous sulphate. Secondly, sodium hydrogenphosphate could be produced easily with high purity and without harmful elements.

Claims

Claim:

1- A process for the stabilizing of ferrous sulphate by: a: adding an amount of diluted sulphuric acid to the reactor and then adding, at a suitable rate, a second reactant which is metallic iron. b: adding sodium hydrogenphosphate at the near end of the above reaction such that the ratio of sodium hydrogenphosphate to the ferrou sulphate is in the range of 1:99 to 0.7-99.3.

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