CLIAMS:We Claim:

1. A process for manufacturing of briquettes from ferro manganese and/or silico manganese fines, comprising

providing Ferro manganese (FeMn) and/or Silico manganese (SiMn) fines in the size range of 0-10mm preferably 0-3mm in a mixer;

adding finely ground calcined Magnesite powder in amount of 6-10 % by weight to the mix for dry mixing;

adding water in amount of 6-10 % by weight to the dry mix and mixing continued till attaining homogeneity;

allowing the prepared mix to undergo ageing for 4-6 hours; and

obtaining cured briquettes of desired strength and hardness.

2. A process as claimed in claim 1, wherein said ferromanganese and silico manganese fines of the size range of 0 to 10mm preferably 0 to 3mm are mixed with finely ground calcined Magnesite powder(3-5%) and water (3-5%) in a high intensive mixer for specified time of 10 to 15 minutes and then further mixing is done with additional finely ground calcined Magnesite powder(3-5%) mixed with water (3-5%) for specified time of 10 to 15minutes.

3. A process as claimed in anyone of claims 1 or 2 wherein said aging of the mix is done by keeping in a covered area for specified duration preferably for 4 to 6 hours.

4. A process as claimed in anyone of claims 1 to 3, wherein said briquettes are produced involving a briquetting machine by pressing the ready mix between the rollers moving in opposite direction to each other, said rollers having tires mounted thereon and having grooves of size 29x9mm such that when the mix is fed in between the rollers a pressure of 30-40KN/cm2 is generated and briquettes are thus obtained.

5. A process as claimed in anyone of claims 1 to 4, wherein self curing of briquettes is carried out in specified temperature preferably at room temperature for about 16-24 hours.

6. A process as claimed in anyone of claims 1 to 5 wherein said ferro manganese fines provided comprises: Mn:60-70 wt%, Si: 1-2wt%, C: 5-10wt%,P:0.1-0.5wt%,S:0.01-0.05wt%.

7. A process as claimed in anyone of claims 1 to 6 wherein said silico manganese fines provided comprises: Mn:50-60 wt%, Si: 10-20wt%, C: 1-2wt%, P:0.1-0.5wt%, S:0.01-0.05wt%.

8. A process as claimed in anyone of claims 1 to 7 wherein said finely ground calcined Magnesite powder provided comprises :
Brand Name :GLC-200 Mesh
Type: Finely ground calcined Magnesite
MgO: 80-85 wt%
CaO: 2.0-4.0 wt%
SiO2 : 8.0-10.0 wt%
Al2O3 : 0.5-1.0 wt %
Fe2O3 : 0.5-1.0 wt%
LOI : 2-4 wt%
Size : 90% passes through 200 mesh

9. Briquettes suitable for application in metallurgical furnaces comprising:

Ferro manganese (FeMn) in amounts of 90 to 94 % by wt and/or Silico manganese (SiMn) in amounts of 90 to 94 % by wt in fines in the size range of 0-10mm preferably 0-3mm;

finely ground calcined Magnesite powder in amount of 6-10 % by weight;

water in amount of 6-10 % by weight.

10. Briquettes as claimed in claim 9 wherein said finely ground calcined Magnesite powder comprises :
Brand Name :GLC-200 Mesh
Type: Finely ground calcined Magnesite
MgO: 80-85 wt%
CaO: 2.0-4.0 wt%
SiO2 : 8.0-10.0 wt%
Al2O3 : 0.5-1.0 wt %
Fe2O3 : 0.5-1.0 wt%
LOI : 2-4 wt%
Size : 90% passes through 200 mesh.

Dated this the 6th day of February,2015
Anjan Sen
Anjan Sen & Associates
(Applicants Agent)

,TagSPECI:FIELD OF THE INVENTION

The present invention relates to briquettes produced from ferro manganese and silico manganese fines using suitable binder, having improved strength properties suitable for use in metallurgical furnaces and a process for manufacturing of such briquettes obtained thereof. More particularly, the present invention is directed to a process for producing briquettes from ferro manganese and silico manganese fines by using selectively finely ground calcined Magnesite powder as binder for the first time for making such briquettes wherein quantity of Magnesite powder and mixing sequence have been suitably formulated to have good quality briquettes. In this process 0-10 mm of fines preferably 0-3mm is used to make briquettes of size 50x25x15mm3. Advantageously, no other additive is used in the process except the finely ground calcined Magnesite powder as binder and water to the mix of FeMn/ SiMn fines (0-3mm) which is very much non-plastic in nature, in order to form briquettes by applying pressure in briquetting machine. The maximum strength obtained after self curing for 16-24 hrs for the briquettes made with Magnesite powder binder, indicated many fold increase in strength that is from green briquette (54kg/cm2) to self cured (104kg/cm2) with maximum retention under drop test obtained for Magnesite-bonded briquettes produced according to the process of the invention making it suitable for advantageous application in iron and steel making.

BACKGROUND OF THE INVENTION

In is well known and widely reported that briquetting and pelletisation are processes used for agglomeration of fines. It is also reported that agglomeration of iron ore, coal, chrome ore and lime fines are being done for various industrial processes. Binder for agglomeration of these fines is generally controlled quantity of moisture.
Applicants’ Ferro Alloy Plant is the largest producer of Manganese based ferro-alloy in India with average annual production of 1.1 lakh ton of ferro alloy. Ferro manganese and silico manganese fines are the finished product of smelting process done in Sub Merged Arc Furnace. Liquid ferro alloy is tapped from tap hole of the furnace and poured in the sand mould. It is allowed to cool till it solidifies and forms cake. These cakes are fed to double toggle jaw crusher for crushing to the sizes of >60mm, 25-60mm, 12-25mm and 3-12mm. During crushing, fines (0-10mm) fractions are generated and they are screened out. The market value of these fines is low and the demand is small. These fines are very hard and cannot be briquetted using water as the binder.
The co-pending patent application number 1261/KOL/2012 dated 02.11.2012 disclosed a process for producing briquettes from Ferro manganese (FeMn) & Silico manganese (SiMn) fines using resol type phenol formaldehyde as binder and plastic clay as additive resulting in reasonably good strength of briquettes.
In view of the above, development of a process for agglomeration of Ferro manganese (FeMn) & Silico manganese (SiMn) fines (0-10mm) by briquetting has been attempted by way of the present invention to achieve still better quality and improved strength of briquettes. Experimental study on the prospect of converting ferro alloys fines (Size < 3mm) into agglomerates by briquette making was taken up. Ferro manganese (FeMn) & Silico manganese (SiMn) fines (0-3mm) were mixed with different binders and additives in a mixer and briquettes were made using briquetting machine and resulting strength of briquettes were tested after controlled curing to decide on the selection and optimum use of ingredients and determining the process parameters to achieve desired best quality of briquettes.

OBJECTS OF THE INVENTION

The basic object of the present invention is directed to briquettes suitable for application in metallurgical furnaces and also to a process for producing such briquettes from ferro manganese and silico manganese fines using ground calcined Magnesite Powder of desired fineness as binder to achieve improved strength and shatter index of briquettes suitable for application in metallurgical furnaces.

A further object of the present invention is directed to a process for producing briquettes from ferro manganese and silico manganese fines which can be sold at the same rates at which other sized ferro manganese alloys are being sold favouring higher revenue earning of Ferro Alloy Plant.

A still further object of the present invention is directed to a process for producing briquettes from ferro manganese and silico manganese fines so as to avoid environmental problem for storage of fines.

A still further object of the present invention is directed to a process for producing briquettes from ferro manganese and silico manganese fines to provide technological solution for using these fines in the metallurgical furnaces as these briquettes will participate more effectively in any metallurgical process.

A still further object of the present invention is directed to a process for producing briquettes from ferro manganese and silico manganese fines wherein selective binder and water are used with fines for briquetting such that the briquettes get some plasticity which will bear the stress during and after manufacturing of briquettes avoiding appearance of cracks and scratches.

A still further object of the present invention is directed to a process for producing briquettes from ferro manganese and silico manganese fines wherein quantity of binder and mixing sequence had been suitably formulated to have good quality briquettes.

A still further object of the present invention is directed to a process for producing briquettes from ferro manganese and silico manganese fines which will have sufficient strength so as to maintain its shape and size during transportation.

A still further object of the present invention is directed to a process for producing briquettes from ferro manganese and silico manganese fines which when charged in metallurgical furnaces like sub merged arc furnace, arc furnace, basic oxygen furnace or steel ladle, it easily melts with the steel due to higher density of these briquettes and contributes in deciding the chemistry of liquid steel.

SUMMARY OF THE INVENTION

The basic aspect of the present invention is thus directed to a process for manufacturing of briquettes from ferro manganese and/or silico manganese fines, comprising

providing Ferro manganese (FeMn) and/or Silico manganese (SiMn) fines in the size range of 0-10mm preferably 0-3mm in a mixer;

adding finely ground calcined Magnesite powder in amount of 6-10 % by weight to the mix for dry mixing;

adding water in amount of 6-10 % by weight to the dry mix and mixing continued till attaining homogeneity;

allowing the prepared mix to undergo ageing for 4-6 hours; and

obtaining cured briquettes of desired strength and hardness.

A further aspect of the present invention is directed to said process wherein said ferromanganese and silico manganese fines of the size range of 0 to 10mm preferably 0 to 3mm are mixed with 3-5 % Magnesite powder mix in a high intensive mixer for specified time of 10 to 15 minutes and then further mixing is done by slow addition of remaining 3-5 % Magnesite powder mix for specified time of 10 to 15minutes.

A still further aspect of the present invention is directed to said process wherein said Magnesite powder is mixed with same quantity of water (6-10%) to have a binder mix for mixing with ferro manganese and/or silico manganese fines.

A still further aspect of the present invention is directed to said process wherein said briquettes are produced involving a briquetting machine by pressing the ready mix between the rollers moving in opposite direction to each other, said rollers having tires mounted thereon and having grooves of size 29x9mm such that when the mix is fed in between the rollers a pressure of 30-40KN/cm2 is generated and briquettes are thus obtained.

A still further aspect of the present invention is directed to said process wherein self curing of briquettes is carried out in specified temperature preferably at room temperature for about 16-24 hours to get the required quality of the briquettes.

A still further aspect of the present invention is directed to said process wherein said ferro manganese fines provided comprises: Mn:60-70 wt%, Si: 1-2wt%, C: 5-10wt%,P:0.1-0.5wt%,S:0.01-0.05wt%.

A still further aspect of the present invention is directed to said process wherein said silico manganese fines provided comprises: Mn:50-60 wt%, Si: 10-20wt%, C: 1-2wt%, P:0.1-0.5wt%, S:0.01-0.05wt%.

A still further aspect of the present invention is directed to said process wherein said finely ground calcined Magnesite powder provided comprises :
Brand Name :GLC-200 Mesh [Manufacturer : SAIL Refractory Company Limited, Salem (TN)]
Type: Finely ground calcined Magnesite
MgO: 80-85 wt%
CaO: 2.0-4.0 wt%
SiO2 : 8.0-10.0 wt%
Al2O3 : 0.5-1.0 wt %
Fe2O3 : 0.5-1.0 wt%
LOI : 2-4 wt%
Size : 90% passes through 200 mesh

Thus according to yet another aspect of the present invention there is provided briquettes suitable for application in metallurgical furnaces comprising:

Ferro manganese (FeMn) in amounts of 90 to 94 % by wt and/or Silico manganese (SiMn) in amounts of 90 to 94 % by wt in fines in the size range of 0-10mm preferably 0-3mm;

finely ground calcined Magnesite powder in amount of 6-10% by weight;

water in amount of 6-10 % by weight.

According to another aspect of the present invention the briquettes suitable for application in metallurgical furnaces include

finely ground calcined Magnesite powder provided comprises :
Brand Name :GLC-200 Mesh [Manufacturer : SAIL Refractory Company Limited, Salem (TN)]
Type: Finely ground calcined Magnesite
MgO: 80-85 wt%
CaO: 2.0-4.0 wt%
SiO2 : 8.0-10.0 wt%
Al2O3 : 0.5-1.0 wt %
Fe2O3 : 0.5-1.0 wt%
LOI : 2-4 wt%
Size : 90% passes through 200 mesh

The various other objects and advantages of the present invention are described in greater details with reference to the following accompanying non limiting illustrative drawings and example.

BRIEF DECSRIPTION OF THE ACCOMPANYING DRAWINGS

Figure 1: is the graphical plot of Shatter index and breaking load of briquettes formed comparing with finely ground calcined Magnesite powder (GLC) vs other binders.

Figure 2: is the photograph showing the arrangements of briquetting machine which is used for making briquettes following the process according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS.

The present invention is directed to developing a process for briquetting of ferro manganese and silico manganese fines in the size range of 0-10mm preferably 0-3mm so that the briquettes have sufficient strength to maintain its shape and size during transportation and charging in metallurgical furnace for effective contribution to metallurgical process in steel making. These briquettes will be charged in to the metallurgical furnaces like sub merged arc furnace, arc furnace, basic oxygen furnace or steel ladle. Charging of fines in these furnaces affects the metallurgical process like steel melting and refining. It also affects the effectivity of the gas cleaning plants. Due to higher density of these briquettes it easily melts with the steel and contributes in deciding the chemistry of liquid steel.

Finely ground calcined Magnesite powder has been used for the first time for making briquettes from ferro manganese and silico manganese fines according to the present process. Quantity of Magnesite powder and mixing sequence have been suitably formulated to achieve good quality briquettes.

Selection of commercially available finely ground calcined Magnesite powder(GLC) as a binder thus helps attaining the desired strength and shatter index of briquettes produced by the process. As FeMn/ SiMn fines (0-3mm) fines are very much non-plastic in nature and even after mixing with different binders it doesn’t generate any plasticity/ workability to form briquettes by applying pressure in briquetting machine. Thus addition of binder and water in the process immediately helps in developing plasticity and thus good briquettes could be made. Here no additive was used.

The process of agglomeration and briquetting of ferro manganese and silico manganese fines according to the present invention is further illustrated as per the following Example I:

EXAMPLE I:

For manufacturing of briquettes five batch compositions were formulated and briquettes were made using different combination of binders with or without additives. As the fines of Ferro manganese (FeMn) & Silico manganese (SiMn) were having no plasticity; the quantity of binder and water with/without additives was optimized to get stable size briquettes.
In the above example, Ferro manganese and silico manganese fines, finely ground calcined Magnesite powder comprised

FeMn & SiMn fines
Product?
Constituents?
FeMn
(%) SiMn
(%)
Mn 60-70 50-60
Si 1-2 10-20
C 5-10 1-2
P 0.1-0.5 0.1-0.5
S 0.01-0.05 0.01-0.05

Finely ground calcined Magnesite powder
Constituents
Values

Brand Name
GLC-200 Mesh
[Manufacturer : SAIL Refractory Company Limited, Salem (TN)]
Type Finely ground calcined Magnesite
MgO 80-85%
CaO 2.0-4.0%
SiO2 8.0-10.0%
Al2O3 0.5-1.0 %
Fe2O3 0.5-1.0 %
LOI 2-4%
Size 90% passes through 200 mesh

According to a preferred aspect of the present invention finely ground calcined Magnesite powder is added as binder in amount of 6-10 % by weight and water is added in amount of 6-10 % by weight.

Ferro manganese (FeMn) & Silico manganese (SiMn) fines were taken in a laboratory mixer. Dry mixing of ferro alloy fines and half of the Magnesite powder (3-5%) was done. Water (3-5%) was added and mixing was done. After that remaining Magnesite powder (3-5%) was mixed with Water (3-5%) and mixing was done till homogeneity. Prepared mix was left aside for aging for 4-6 hours. After aging briquettes were made in a laboratory briquetting machine. Briquettes were self cured for 16-24 hours.

Thus according to the exemplary illustration of the process according to the present invention following steps are followed:

(i) providing ferromanganese and silico manganese fines of the size range of 0 to 10mm preferably 0 to 3mm in a high intensive mixer for initial mixing with Magnesite powder (3-5%) and Water (3-5%) for specified time (10 to 15 minutes);
(ii) further final mixing carried out in the mixer with Magnesite powder (3-5%) and Water (3-5%) mix for specified time (10 to 15 minutes);
(iii) Keeping the mix thus obtained thereafter in a covered area for specified duration preferably 4 to 6 hours for aging; and
(iv) pressing the mix in briquetting machine at specified pressure of 30 to 40 KN/cm2 to form desired briquette of size 50x25x15mm3;
(v) self curing of briquettes thus produced in specified temperature preferably at room temperature,

The briquettes obtained following the above process of the invention was found to have the following composition:

Ferro manganese (FeMn) in amounts of 90 to 94 % by wt or Silico manganese (SiMn) in amounts of 90 to 94 % by wt in fines in the size range of 0-10mm preferably 0-3mm;

finely ground calcined Magnesite powder in amount of 6-10% by weight;

water in amount of 6-10 % by weight.

Testing of Briquettes:

After curing briquettes were tested for breaking load and drop test. Initial strength was found low. To increase the strength briquettes were self cured for 16-24 hrs.

From the test results it was found that for green briquettes maximum strength (breaking load) was obtained (54kg), when the briquettes were cured at room temperature for 16-24 hours.
Similarly after shatter test i.e. dropping the briquette (2kg) from a height of 2 meter and retention on 10 mm screen up to 4 drops. Maximum retention obtained was for Magnesite-bonded briquette (97.5% after 1st drop and 85% after 4th drop). For resin-bonded briquettes of prior art, it was 97.5% for 1st drop and 76% for 4th drop.

These briquettes are stored in the briquetting plant and later on it will be fed to series of belt conveyors before charging it to metallurgical furnaces. During this process of transportation of briquettes there will be number of falls for the briquettes. To check the ability of the briquettes to retain its size during transportation Shatter test was conducted. Accompanying Figure 1 illustrates the result and comparison of shatter test of briquettes made with different combination of binders.

Figure 2 illustrates the arrangement of briquetting machine. Briquettes are produced by pressing the ready mix between the rollers moving in opposite direction to each other. These rollers have tires mounted on it having groves of size 29x9mm. When the mix is fed in between the rollers a pressure of 30-40KN/cm2 is generated and briquettes are made.

Strength is the combined effect of binder and specific pressure during briquetting. Briquettes produced tries to release the pressure applied on them as normal phenomena of material. During this process slight expansion is there on the briquettes and due to this cracks and lamination occurs. Fineness of the binder material provides plasticity to the mix which accommodates the stress and later on expansion and saves the briquettes from cracks or lamination. With the use of finely ground calcined Magnesite powder as a binder breaking load was found to be highest when the briquettes were self cured for 16 to 24 hours as can be seen in Figure 1.

It is thus possible by way of the present invention to providing a process for producing briquettes from ferro manganese and silico manganese fines using selective binder and water so that superior quality of cured briquettes is ensured in terms of strength and maximum retention under drop test making these briquettes fit for economic industrial utilization in iron and steel making, maintaining the shapes during transit.

We Claim:

1. A process for manufacturing of briquettes from ferro manganese and/or silico manganese fines, comprising

providing Ferro manganese (FeMn) and/or Silico manganese (SiMn) fines in the size range of 0-10mm preferably 0-3mm in a mixer;

adding finely ground calcined Magnesite powder in amount of 6-10 % by weight to the mix for dry mixing;

adding water in amount of 6-10 % by weight to the dry mix and mixing continued till attaining homogeneity;

allowing the prepared mix to undergo ageing for 4-6 hours; and

obtaining cured briquettes of desired strength and hardness.

2. A process as claimed in claim 1, wherein said ferromanganese and silico manganese fines of the size range of 0 to 10mm preferably 0 to 3mm are mixed with finely ground calcined Magnesite powder(3-5%) and water (3-5%) in a high intensive mixer for specified time of 10 to 15 minutes and then further mixing is done with additional finely ground calcined Magnesite powder(3-5%) mixed with water (3-5%) for specified time of 10 to 15minutes.

3. A process as claimed in anyone of claims 1 or 2 wherein said aging of the mix is done by keeping in a covered area for specified duration preferably for 4 to 6 hours.

4. A process as claimed in anyone of claims 1 to 3, wherein said briquettes are produced involving a briquetting machine by pressing the ready mix between the rollers moving in opposite direction to each other, said rollers having tires mounted thereon and having grooves of size 29x9mm such that when the mix is fed in between the rollers a pressure of 30-40KN/cm2 is generated and briquettes are thus obtained.

5. A process as claimed in anyone of claims 1 to 4, wherein self curing of briquettes is carried out in specified temperature preferably at room temperature for about 16-24 hours.

6. A process as claimed in anyone of claims 1 to 5 wherein said ferro manganese fines provided comprises: Mn:60-70 wt%, Si: 1-2wt%, C: 5-10wt%,P:0.1-0.5wt%,S:0.01-0.05wt%.

7. A process as claimed in anyone of claims 1 to 6 wherein said silico manganese fines provided comprises: Mn:50-60 wt%, Si: 10-20wt%, C: 1-2wt%, P:0.1-0.5wt%, S:0.01-0.05wt%.

8. A process as claimed in anyone of claims 1 to 7 wherein said finely ground calcined Magnesite powder provided comprises :
Brand Name :GLC-200 Mesh
Type: Finely ground calcined Magnesite
MgO: 80-85 wt%
CaO: 2.0-4.0 wt%
SiO2 : 8.0-10.0 wt%
Al2O3 : 0.5-1.0 wt %
Fe2O3 : 0.5-1.0 wt%
LOI : 2-4 wt%
Size : 90% passes through 200 mesh

9. Briquettes suitable for application in metallurgical furnaces comprising:

Ferro manganese (FeMn) in amounts of 90 to 94 % by wt and/or Silico manganese (SiMn) in amounts of 90 to 94 % by wt in fines in the size range of 0-10mm preferably 0-3mm;

finely ground calcined Magnesite powder in amount of 6-10 % by weight;

water in amount of 6-10 % by weight.

10. Briquettes as claimed in claim 9 wherein said finely ground calcined Magnesite powder comprises :
Brand Name :GLC-200 Mesh
Type: Finely ground calcined Magnesite
MgO: 80-85 wt%
CaO: 2.0-4.0 wt%
SiO2 : 8.0-10.0 wt%
Al2O3 : 0.5-1.0 wt %
Fe2O3 : 0.5-1.0 wt%
LOI : 2-4 wt%
Size : 90% passes through 200 mesh.

Dated this the 6th day of February,2015
Anjan Sen
Anjan Sen & Associates
(Applicants Agent)

ABSTRACT
TITLE: BRIQUETTES FROM FERRO MANGANESE AND/OR SILICO MANGANESE FINES AND A PROCESS FOR MANUFACTURING THE SAME.

Briquettes from ferro manganese and/or silica manganese fines and to a process for manufacturing from the same involving ferro manganese and silico manganese fines of 0-10 mm preferably 0-3mm size, by using selectively finely ground calcined Magnesite powder as binder in desired quantity and a mixing sequence selectively followed to have good quality briquettes. Advantageously, fineness of binder replaces the use of an additive in the process of briquette making to impart plasticity/ workability to the mix of FeMn/SiMn fines with binder which is very much non-plastic in nature, in order to form briquettes by applying pressure in briquetting machine. The maximum strength obtained after self curing for the briquettes made with finely ground calcined Magnesite powder as binder, indicated many fold increase in strength from 54kg/cm2 for green briquette to 104kg/cm2 for self cured briquettes for 16-24 hours with maximum retention under drop test obtained for finely ground calcined Magnesite powder - bonded briquettes making it suitable for advantageous application in iron and steel making.
(Figure 1)