The present invention relates to refractory lining of metallurgical furnace and more particularly it discloses a method of production of silica ramming mass containing alumina comprising a programmed electronically-controlled automated ball-mill based process.
BACKGROUND OF INVENTION:
EP0049366A1 titled 'Refractory dry ramming mix based on zirconium oxide for lining crucible induction furnaces' describes a refractory dry ramming mass based on partially stabilized zirconium oxide for lining induction furnaces for melting of high-alloy stainless steels; Nickel-based alloys, nickel-chromium-based alloys and special alloys with improved resistance to thermal shock and over the molten metal at temperatures of 1650 ° C and with an increased resistance of the liner against premature sintering.
In EP0005482A1 titled 'Refractory dry ramming mix for lining crucible induction furnaces' dry ramming mass for lining in crucible induction furnace is disclosed which consists of Alumina in form of

fused or sintered alumina as the principal material and additive containing MgO.
Traditionally, hammer-based crushers comprising manganese plates are used for crushing quartz resulting into manganese fines getting mixed in crushed product. The magnetic separators cannot separate manganese fines. Moreover, in induction furnaces, there is a need for ramming mass which can withstand the higher temperatures rising upto 1700° Celsius for a greater length of time. Also, a more efficient production process for silica ramming mass is required.
OBJECT OF INVENTION:
It is the primary object of the present invention to provide a means to produce silica ramming mass based on ball-mill production technique using alumina grinding media balls.
It is yet another object of the present invention to provide a means to produce silica ramming mass employing three stage crushing process involving the use of vertical shaft impact crusher.
It is yet another object of the present invention to use said vertical shaft impact crusher comprising chromium plates.
It is also an object of the present invention to provide for an automated means to produce silica ramming mass wherein said

automated means removes raw material impurities and impurity of manganese steel fines generated during the process.
SUMMARY OF INVENTION:
One of the embodiments of the present disclosure discloses a method of production of silica ramming mass containing alumina. In the production of said silica ramming mass, quartz is used as raw material. The said process of producing said ramming mass containing alumina comprises of three (3) stages crushing of said raw material. Firstly, the two stages of crushing are performed using a primary jaw crusher and secondary crusher. The said process of crushing through said primary jaw crusher and said secondary crusher generate impurities of iron and manganese steel fines within said raw material crushed to 0-2mm size. The said impurities generated during first two stages are removed by an automated means. The third stage of crushing of said raw material obtained after crushing through said primary jaw crusher and said secondary crusher is performed through a vertical shaft impact crusher in which said raw material is crushed by said raw material and does not employ iron or manganese hammer-based crushers. The said vertical shaft impact crusher comprises of chromium plates. The said raw material obtained from said vertical shaft impact crusher is differentiated by size and sent to more than one silos. The said raw material stored in said more than one silos are crushed to powder form in a ball-mill comprising High Alumina balls.

DETAILED DESCRIPTION:
The present disclosure discloses a method of production of silica ramming mass containing alumina. The following description with reference to accompanying drawing/flow chart is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of patent application and its requirements.
According to present disclosure, quartz stone is used as raw material to produce said silica ramming mass. The said raw material is fed into a feeder hopper. The said raw material is fed into a primary jaw crusher from said feeder hopper. The said primary jaw crusher crushes said raw material having size range from 125 mm to 500 mm gives out a primary output stone of size ranging from 100 mm to 125 mm. The said primary output stone is, then, fed into a secondary crusher. The said secondary crusher reduces said primary output stone into a secondary output stone having size ranging from 2 mm to 35 mm. At least one vibrating screen performs the sizing of said secondary output stone and said at least one vibrating screen segregates said secondary output stone having size upto 2 mm containing impurities. The said secondary output stone having size larger than 35 mm is again fed into said secondary jaw crusher. The said secondary output stone having size ranging from 2 mm to 35 mm are stored in at least one silo. The said at least one silo works as buffer storage before feeding said secondary output stone into two vertical shaft impact (VSI) crushers.

The said secondary output stone having size ranging from 2 mm to 35
mm stored in at least one silo is put into one of said two VSI crushers.
In one of the embodiment of present disclosure having two (2) VSI
crushers, each one of said VSI crushers operates for maximum 6 hours.
5 Only one of the said two VSI crushers operates at a time. The said VSI
crushers comprise chromium plates. The said VSI crusher further
comprises atleast one rotor which rotates at speed ranging between
1600-1900 rotations per minute. The said secondary output stone is fed
into one of said VSI crusher in two batches. The said secondary output
10 stone crushes to give a third output stone having size upto 7 mm.
An output from said VSI crusher having size above 7 mm is separated from said third output stone through said atleast one vibrating screen. The said separated output of said VSI crusher having size above 7 mm
15 is again fed into said VSI crusher to obtain said third output stone
having size ranging upto 7 mm. The said third output stone having size upto 7 mm is passed through magnetic separator to separate manganese fines mixed into said third output stone during crushing in said one of the VSI crushers. The said third output stone having size ranging upto 7
20 mm is segregated into size range of 6-7 mm, 5-6 mm, 4-5 mm, 3-4
mm, 2-3 mm and upto 2 mm by said atleast one vibrating screen. The said segregated third output stone of six size range are stored in six (6) silos namely silo 1, silo 2, silo 3, silo 4, silo 5 and silo 6, respectively. The said segregated third output stone stored in six silos are called
25 grains.
6

The said segregated third output stone stored in any one of said six silos is fed into a ball-mill to grind said segregated third output stone to obtain powder of 150 Mesh. The said ball-mill uses balls made of High Alumina as grinding media. The said powder having size of 150 Mesh of any of said segregated third output stone stored in respective silo is segregated and stored in one of two separate silo through atleast one vibrating screen and a powder output from said ball-mill larger than 150 Mesh is again fed into said ball-mill. The said powder of each of said third output stone as obtained from said ball-mill is called ball-mill powder.
In one of the embodiment of present disclosure the said ball-mill powder is mixed in required proportion in atleast two mixers operated and controlled through a programmable logic control (PLC) system. Each of said six silos storing said grains and two silos containing said ball-mill powder is connected to said PLC system which takes required amount of said grains from said six silos and said ball-mill powder stored in said two silos to one of said atleast two mixers.
The said atleast two mixers are programmed through said PLC system to mix said said grains and said ball-mill powder in required proportion to obtain one batch of ramming mass containing alumina. Each batch of said ramming mass containing alumina weighs 1 ton.

WE CLAIM:

A process for producing silica ramming mass, the process comprising:
crushing of raw material which is quartz stone in a primary jaw crusher to obtain a primary output stone having size range of 100 mm to 125mm;
crushing of said primary output stone in a secondary crusher to obtain a secondary output stone having size range of 2 mm to 35 mm;
removing said secondary output stone having size range upto 2 mm;
crushing of said secondary output stone by atleast one vertical shaft impact (VSI) crusher to obtain third output stone having size range upto 7mm;
segregating said third output stone through atleast one vibrating screen in six (6) sizes and storing said segregated six (6) sizes of said third output stone in six (6) silos;
grinding one out of said six sizes of third output stone in a ball-mill consisting of High Alumina grinding media balls to obtain ball-mill powder;
mixing of said ball-mill powder with said six sizes of third output stone stored in said six number of silos in required proportion through atleast one programmable logic control (PLC) system-controlled mixer.

A process of producing silica ramming mass as claimed in claim
1, wherein said raw material is quartz stone of size ranging from
125 mm to 500 mm.
A process of producing silica ramming mass, as claimed in claim 1, wherein said secondary output stone collide with said secondary output stone due to rotation of a rotor placed inside said VSI crusher rotating at a speed of 1600-1900 rotations per minute.
A process of producing silica ramming mass, as claimed in claim
3, wherein said chromium fines from the chromium plates
comprised in said VSI crusher mixes in said third output stone
during collision and crushing in said VSI crusher.
A process of producing silica ramming mass, as claimed in claim
4, wherein said chromium fines are separated from said third
output stone by passing said third output stone through a
magnetic separator.
A process of producing silica ramming mass as claimed in claim 1, wherein said third output stone is segregated in size range of 1-2 mm, 2-3mm, 3-4mm, 4-5mm, 5-6mm and 6-7mm and stored in said six silos.

A process of producing silica ramming mass as claimed in claim 1, wherein High Alumina mixes with said third output stone while grinding in said ball mill.
A process of producing silica ramming mass as claimed in claim 1, wherein said atleast one programmable logic control (PLC) system-controlled mixer takes said ball-mill powder and said third output stone stored in said six silos in required proportion as input to obtain said ramming mass containing alumina weighing 1 ton in 1 batch.
A process of producing silica ramming mass, as claimed in claim 1, wherein impurities of size upto 2 mm in said raw material is removed by atleast one vibrating screen.