Improved method for producing finely divided haematite and for producing iron oxide red pigments

A technology of iron oxide red and hematite, applied in the field of iron oxide red pigment, can solve the problems of unpredictable reaction process, fluctuating conversion rate of iron nitrate, less stability, etc., and achieves the effect of high reliability

Active Publication Date: 2013-04-10
LANXESS DEUTDCHLAND GMBH
View PDF14 Cites 15 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In addition, under these reaction conditions the conversion of iron relative to the nitric acid used fluctuates, i.e. the process does not proceed in a steady manner
It was found that the quality of iron used under these conditions also had an effect on the conversion of iron relative to the nitric acid used making the course of the reaction less predictable and less stable from reaction to reaction

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0079] 8.44kg (151.1mol) of iron punching (metal) plate (iron punching sheet, iron punching sheet) (thickness 0.8mm) was placed in 61.3kg of water and heated to 80°C. 18.67 kg of 30 wt% nitric acid (88.9 mol) at a feed rate of 1851 g / min were added over a period of 10 min. The amount of nitric acid added corresponds to an initial calculated concentration of 7% by weight in the reaction mixture. The temperature of the reaction mixture increased to a maximum of 151° C. and the pressure increased and was limited to 4.3 bar within 20 minutes after the end of the nitric acid addition. A suspension of hematite was produced and 12.06 kg of finely divided hematite were thus obtained after filtration and drying of the residue. The hematite obtained in this way has a BET surface area of ​​48m according to DIN66131 2 / g. The molar conversion factor for metallic iron was 1.7 based on the nitric acid used.

Embodiment 2

[0081] 5.42 kg (97.1 mol) of iron wire pins (nails) were placed in 68.2 kg of water and heated to 80°C. 11.84 kg of 30.4 wt% nitric acid (57.1 mol) were fed at a feed rate of 1174 g / min over a period of 10 min. The amount of nitric acid added corresponds to an initial calculated concentration of 4.5% by weight in the reaction mixture. The temperature of the reaction mixture increased to a maximum of 125° C. and the pressure increased and was limited to 4.5 bar within 60 min after the end of the nitric acid addition. A suspension of hematite was produced and 6.54 kg of finely divided hematite were thus obtained after filtration and drying of the residue. The hematite obtained in this way has a BET surface area of ​​73m according to DIN66131 2 / g. The molar conversion factor for metallic iron was 1.43 based on the nitric acid used.

Embodiment 3

[0083] 8.44kg (151.1mol) of wire pins (nails) were placed in 61.3kg of water and heated to 95°C. 18.67 kg of 30 wt% nitric acid (88.9 mol) were added at a feed rate of 1851 g / min over a period of 10 min. The amount of nitric acid added corresponds to an initial calculated concentration of 7% by weight in the reaction mixture. The temperature of the reaction mixture rose to a maximum of 143[deg.] C. and the pressure increased and was limited to 3.4 bar within 30 minutes after the end of the nitric acid addition. A suspension of hematite was produced and 10.67 kg of finely divided hematite were thus obtained after filtration and drying of the residue. The hematite obtained in this way has a BET surface area of ​​51m according to DIN66131 2 / g. The molar conversion factor for metallic iron was 1.5 based on the nitric acid used.

[0084] Particle size: The finely divided hematite produced according to the present invention has a particle size less than or equal to 100 nm. 90%...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
particle diameteraaaaaaaaaa
specific surface areaaaaaaaaaaa
particle diameteraaaaaaaaaa
Login to view more

Abstract

The invention relates to an improved method for producing finely divided haematite and iron oxide red pigments. The iron oxide red pigments are composed of the finely divided haematite. The invention also relates to the use of the finely divided haematite and iron oxide red pigments produced according to said method. The finely divided haematite produced by the method has a grain size less than or equal to 100 nm and a 40 m<2> / g-150 m<2> / g BET specific area ( measured according to DIN 66131). The method comprises: a)providing a mixture of metal iron and water having a temperature of 60-120 DEG C; b) adding dilute nitric acid in the mixture of step a; c) separating the water suspension of finely divided haematite from any metal not reacting; d) selectively separating the finely divided haematite from the separated water suspension.

Description

technical field [0001] The present invention relates to an improved method for producing finely divided haematite and iron oxide red pigment (iron oxide red) composed of finely divided hematite and finely divided hematite produced by this method And the use of iron oxide red pigment. Background technique [0002] Iron oxides are used in many industrial fields. Thus, they are used, for example, as color pigments for ceramics, building materials, plastics, surface coatings and paper, as base or carrier materials for various catalysts, and for adsorbing or absorbing pollutants. Magnetic iron oxides are used in magnetic memory media, toners, ferrofluids or in medical applications such as contrast agents for magnetic resonance tomography. [0003] In many of these applications, the particle size of the iron oxide particles plays a key role. Particles with a particle size of less than or equal to 100 nm are required for applications in which the technical effect is determined b...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C01G49/06
CPCC01P2006/12C01P2004/64C09C1/24C01P2006/80C01G49/06B82Y30/00Y10T428/2982
Inventor 吉多·克特勒乌多·奥尔特曼于尔根·基施克维茨
Owner LANXESS DEUTDCHLAND GMBH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap