Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for producing granular metal

a technology of granular metal and granular particles, which is applied in the direction of basic electric elements, rotary drum furnaces, electric devices, etc., can solve the problems of increasing the amount of by-product slag, affecting the cohesion property of slag, and imposing large limitations on the types of carbonaceous reductants, etc., to achieve long-term continuous operation, prolong the life of hearth refractories, and increase the rate of large metallic iron nu

Inactive Publication Date: 2004-08-12
KOBE STEEL LTD
View PDF26 Cites 31 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0017] Moreover, the cohesion property of the by-product slag may also decrease even when the gangue content in the material is low, depending on the types of the iron oxide source, the slag components, and slag composition. An improvement as to this point is also desired.
[0047] When a metal source, such as steel-making slag, that contains large amounts of slag components is used, an excessive amount of by-product slag relative to the metal nuggets is produced and inhibits the cohesion of the metal, thereby decreasing the recovery rate of large metal nuggets. Accordingly, in order to prevent an increase in the amount of the by-product slag and to improve the recovery rate of the large metal nuggets, the slag component content in the material mixture should be as low as is feasibly possible. In particular, the slag component content in the material mixture is preferably controlled so as to limit the amount of the slag to approximately 500 kg per ton of the metal nuggets.

Problems solved by technology

However, a large degree of limitation is imposed as to the types of the applicable carbonaceous reductant.
In these cases, the amount of by-product slag increases, and the degradation of the cohesion property of the slag is inevitable, which is a problem.

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

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method for producing granular metal
  • Method for producing granular metal
  • Method for producing granular metal

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0050] In this example, magnetite iron ore having a high gangue content, and more specifically, a high SiO.sub.2 content of 5.0% or more, was used as an iron oxide source. The chemical composition of the ore is shown in Table 1.

1TABLE 1 Chemical Composition of Material Iron Ore Having a High SiO.sub.2 Content (mass %) T.Fe Fe.sub.2O.sub.3 Fe.sub.3O.sub.4 SiO.sub.2 Al.sub.2O.sub.3 CaO MgO Other Total 67.21 1.15 91.77 5.4 0.28 0.81 0.45 0.14 100

[0051] The designed composition of high-SiO.sub.2 iron ore, a carbonaceous reductant, a binder (wheat flour), CaCO.sub.3 (basicity adjustor), and CaF.sub.2 (cohesion accelerator) in the material pellets was adjusted as shown in Table 2.

2TABLE 2 Designed Composition of the Material Pellets (mass %) Case A Case B (Comparative (Comparative Case C Case D Composition Example) Example (Example) (Example) High-SiO.sub.2 78.88 72.33 73.42 71.23 iron ore Coal 19.62 18.17 17.08 17.77 (carbonaceous reductant) Binder 1.5 1.5 1.5 1.5 CaCO.sub.3 0 8 7 8.5 Ca...

case b

[0056] Case A was compared with Case B, in which the amount of the by-product slag was increased due to the addition of 8% of CaCO.sub.3, clearly demonstrated a tendency of an increase in the production rate of metallic iron nuggets having a small diameter. The recovery rates of the metallic iron nuggets of (1) 0.2 g or more and (2) 1.0 gram or more were clearly low. Particularly the recovery rate of the metallic iron nuggets having a mass of 1.0 g or more decreased by 12% or more. It should be noted that in Case B, large amounts of micro particles of metallic iron adhered onto the surface of the by-product slag, and those metallic iron nuggets that existed separately from the slag enclosed slag particles. Thus, the separation of the metallic iron nuggets from the slag was difficult.

[0057] On the other hand, when Case B was compared with Case C, although the amount of the by-product slag was increased in both Case C and Case B, Case C demonstrated that the cohesion of the molten me...

example 2

[0065] In this example, iron ore having a poor cohesion property, i.e., hematite ore, was used in the material to confirm the effect of adding approximately 1.0% of CaF.sub.2 as the cohesion accelerator. The experiments of reducing melt were conducted as in Example 1 above.

[0066] Table 6 shows the primary chemical composition of the hematite ore used in the experiment. FIGS. 3 and 4 include photographs showing the appearances of the state of the products immediately after the reducing melt (FIG. 3) on an aluminum board tray and the recovered metallic iron nuggets (FIG. 4) obtained in Case F which implements the present invention and uses CaF.sub.2 as the cohesion accelerator. FIGS. 3 and 4 also include photographs showing the appearances of the state of the products immediately after the reducing melt (FIG. 3) on an aluminum board tray and the recovered metallic iron nuggets (FIG. 4) obtained in Case E which is a comparative example that does not use CaF.sub.2.

6TABLE 6 Chemical Comp...

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
temperatureaaaaaaaaaa
temperatureaaaaaaaaaa
temperatureaaaaaaaaaa
Login to View More

Abstract

A method for making metal nuggets comprises heating a material containing a metal-oxide-containing substance and a carbonaceous reductant to reduce metal oxide in the material and then further heating the produced metal so as to melt the metal while allowing the metal to separate from a by-product slag component and to form granular iron. A cohesion accelerator for the by-product slag is mixed into the material to produce metal nuggets having a high metal purity, a large diameter, and superior transportation and handling qualities at a high yield and high productivity.

Description

[0001] The present invention relates to methods for manufacturing metal nuggets. In particular, the present invention relates to an improved method for manufacturing high-purity metal nuggets such as iron nuggets that have a large diameter and superior transportation and handling qualities, the method including heating a mixture of a metal-oxide-containing substance and a carbonaceous reductant to reduce the metal oxide, in which an auxiliary material for increasing the fluidity of and promoting the cohesion of molten by-product slag is added to the material. The improved method achieves a high yield and high productivity.[0002] This specification mainly describes a method for manufacturing iron nuggets to which the present invention is most effectively applied. However, the present invention is not limited to the manufacturing of iron nuggets. The present invention can also be effectively applied to the manufacture of ferrochromium or ferronickel by heating and reducing chromium-co...

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(United States)
IPC IPC(8): C22B1/16C21B13/00C21B13/10C22B1/245C22B5/10C22B7/02C22B23/00C22B34/32C22C33/04H01H9/16
CPCC21B13/0046C21B13/008C21B13/105C22B34/32C22B5/10C22B7/02C22B23/00C22B1/245Y02P10/20C21B13/10
Inventor ITO, SHUZOTSUGE, OSAMU
Owner KOBE STEEL LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com