FORM-2
THE PATENTS ACT, 1970
COMPLETE
SPECIFICATIONS
(SEE SECTION 10)

TITLE
NAME

RECLAMATION OF WASTE FOUNDRY SAND HAVING WATER SOLUBLE ORGANIC BINDER CURED BY CO2GAS with SIMPLEX & DUPLEX RECLAMATION MACHINES.
1. MR. RAGHUVEER CHANDRA KOTHARI
2. MR. MANISH KOTHARI



ADDRESS
NATIONALITY

Having Residence at:
1. Bungalow No. 6,NandResidency,
B/h. Aims Oxygen, ,
Old Padra Road, Baroda-390020 Gujarat-India
2. E-202, Samrajya Flats,
Opp. Sabari Vidhayala,
Vasna Road,
Baroda-390015
Gujarat-India
1). Indian
2). Indian

The following specification particularly describes and ascertain the nature of this invention and the manner in which it is to be performed.
RECLAMATION OF WASTE FOUNDRY SAND HAVING WATER SOLUBLE ORGANIC BINDER CURED BY CO2GAS with SIMPLEX & DUPLEX RECLAMATION MACHINES.
This invention relates to the reclamation of foundry sand wastes, particularly core and moulding sand, so as to use reclaimed sand for a new core and mould manufacture.
In the known art, practically all Foundries operating with the practice of Sodium Silicate Bonded Sand cured by CO2 gas have been using new sand for the preparation of cores and at least for the facing sand for moulding. The Sodium Silicate Bonded Sand once moulded, is not possible to reuse directly in place of new sand, once it has been mixed and cured or hardened by self setting silicates, whether the molten metal comes in contact with the sand or not.
The mould with core, once poured with liquid metal, is broken down after solidification and cooling of the casting. In the process lumps of various sizes and shapes are generated with some part of granular sand.
In normal practice, these lumps are collected and disposed off, which creates both economical and ecological problems, and therefore, it is desirable to upgrade and reclaim these scrapped lumps to new sand quality for reuse in production of cores and moulds.
The problems in reclamation of the discarded sand involve both quality level and uniformity and also economic viability. No known methods for reclamation and reuse of the waste foundry Silicate Bonded Sand have been found to be economically viable and practical for production.
The WET PROCESS is considered and known to be the best method for reclaiming the Silicate Bonded Sands. But, though, the Wet Process renioves all water soluble Silicates, non-soluble Silicates generated by the heat of the metal are not removed by Wet Process. Moreover, water availability, treatment of water for re-circulation, space required, effluent generation and disposal, Den for mosquitoes and insects and Heavy Investment in handling the total Water System are deterrent. TheSILlCATE SAND PROCESS also as per the published literature had some deterrents in that no good reclamation process was getting available by it and collapsibility was also poor. And generally the organic systems are more polluting in that they release Nitrogen and are toxic to the skin. The THERMAL PROCESS is the most versatile process but capital intensive and involves high-energy costs. Also, the Sand grains are restored with no damages in this process. But, as M. H. Lavington has said in the Foundry Trade Journal of April 1985, "Clay and Silicate Bonded Sands cannot be successfully reclaimed Uy Thermal means alone." In the PNEUMATIC RECLAIMER Process, the Single Cell/Dual Cell/Multi-Cell fluidized reclaimers have been tried earlier with a plate at top which are hit by the grains. But in that also, there is High Investment Costs, High Wear and Tear and High Air
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Consumption leading to High Energy costs. In the MECHANICAL ATTRITION CUM PNEUMATIC CLASSFIER PROCESS, which is largely in use for No Bake Plants, there are publications stating categorically that even for NO BAKE Sand Reclamation, to keep LOI low, secondary mechanical attrition by way of Hammer Mill/Rotary Disk disintegrator etc. is needed and for Silicate Sands this appears to be must. It is only feasible for larger capacity plants but such plants are usually unaffordable.
Ecologically also, the known methods are not viatie and contribute to environmental pollution and further cause enhancement of costs, because the Sand Sources of acceptable quality Sands are finite and as stocks deplete, sand will become more difficult to obtain. New Sand Quarrying is mostly suspended in monsoon therefore excessive inventory is to be maintained needing large covered storage space and double handling. Moreover, the more we indulge in mining, the more we become Anti-Nature. Also, the disposal of waste sand becomes an environmental hazard; as many areas are now congested or are getting congested. Therefore, it is increasingly becoming difficult to find adequate dumping grounds. And to add further to it, the disposal of the waste Sand pollutes the atmosphere and affects the greenery and vegetation. And not to say that the costs of transportation to disposal sites become a economical deterrent.
The object of the present invention is to provide a novel and economical method for reclaiming of Sodium Silicate Bonded Sand to be acceptable for the reduction of moulds and cores, in the Foundry.
Another object of the invention is to prevent the need of dumping of the waste sand, which is harmful to the environment and with increased anti-dumping regulations, is becoming an expensive route. The same objective also reduces the foundry's dependence on outside natural sources for new sand, drying of new sand, maintaining inventory/stock of new sand, etc.
Due to reuse of waste sand, the finite sources of sand are conserved, and the mining operations are reduced.
The method used for reclamation also eliminates the need for wet process and thermal process for reclaiming the sand, since these are cumbersome as well as more expensive routes for reclaiming the sand.
The method of reclamation by this inventionis described as below:
a. The lumps are sized between 25 to 100 mm depending on the capacity of the machine
manually or using a specially designed crusher for this application.
b. The lumps are charged in the batch hopper of the reclamation plant attrition shdl. The
quantity of charge is dependent on the size of machine used.
c. The Forced Air Blower for fluidization and Suction Blower for evacuation of dust
laden air are kept in running condition.
d. The main Attrition unit drive is kept in running condition.
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e. The lumps of specified size range and quantity are charged into mechanical attrition
shell.
f. The attrition and fluidization take place simultaneously and the dust/fines generated
are continuously extracted.
g. The majority of dust/fines extracted are collected in the first stage cyclone separator
and the balance very fine particles, which escape the cyclone separator, are trapped in
the bag filter, not allowing polluting dust to escape into the atmosphere beyond
acceptable proportions.
h. The process of attrition & fluidization continues for 8 to 15 minutes, depending on
the input sand type and output sand quality demands, i. Once the designated time of reclamation is over, the batch of reclaimed sand is
discharged from the bottom of the reclamation shell. j. The discharged reclaimed sand shall, consist of a small percentage of residual lumps,
depending on the quality of input sand, and the time spent in reclamation. The lumps,
if present, can be separated using a simple manual screen or a vibrating screen of the
desired mesh size, k. The process loss i.e. the amount of dust/fines collected in the cyclone separator and
dust collector, amounts to 10 to!5% for various qualities of sand. In addition, the loss
of sand recovered for reclamation is also to be accounted. In total about 8)% of the
input waste sand can be considered as available for reuse. 1. The reclaimed sand is completely dry and can be consumed immediately for use in
core and/or moulding as required.
The usage of this process of reclamation is not restricted only to of Sodium Silicate Bonded Sand, but can also be used to reclaim chemically bonded and cured Sands (no bake~), cement bonded sands, etc. The trials for the same are in the phase of development
PRINCIPLE OF RECLAMATION:
RHINO SAND SIMPLEX & DUPLEX SHELL RECLAMATION MACHINE is a simple and effective machine to clean and recover Foundry Knocked Out Sand forReuse as New Sand.
The machine has been developed with Intensive Test Runs of Prototype to find an optimum combination of the two Dry Attrition processes - Mechanical and Fluidised in one machine with continuous removal of dust and fines. Extent of removal of fines and dust can be controlled to suit individual application.
Extensive field trials were conducted with Silicate Bonded Sands. The Reclaimed Sand has been successfully used to make even the Cores in both Steel & S. G. Iron castings with 80% to 85% Reclaimed Sand and only 20 to 15% New Sand.
FEED MATERIAL:
Sand Lumps about 25 to 100mm (avg 40 mm); free from nails, chills tramp metal can be accepted by the machine.
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SYSTEMS DESCRIPTION:
The machine has a batch hopper with a flap gate arrangement. Arrangement for loading the lumps in batch hopper is to be made by the user as per their requirement.
The batch hopper discharges Sand into a shell in which mechanical and fluidized Attrition takes place simultaneously.
The dust and fines are extracted from the Sand with an appropriate dust collection system. For collecting the dust generated, a two-stage dust collection system has been provided. Cyclone separator and Bag Filter together ensure minimum fines escape to the atmosphere.
Depending on the quality of input and the quality of output desired, the average cycle time to clean the Sand is 12 to 18 minutes per batch. Batchto-Batch time of course depends on the Type of Sand / Loading / Unloading etc, 3 batches to 4 batches per hour are obtained in actual production.
The reclaimed sand is discharged through mechanical bottom discharge gate. The useful sand can be collected in suitable container/ wheel barrow for further use.
THE MACHINE CONSISTS OF:
• Reclaimer Shell Simplex Fig -l) or Duplex (Fig -2) The shell receives the material
through batch hopper.
• Simplex Type is Single Shell & Duplex is a Twin Shell Machine. In Duplex first twin
receives the material through batch hopper, and the discharge takes place from the
second twin, or even from both shells simultaneously.
• Cyclone dust separator: Primary separation of fines takes place in cyclone
separator. It is provided with dust box for collection of dist.
• Bag Filter Bag filter collects the fines that escape cyclone separator so that clean air
is discharged to the atmosphere.
• Blowers: Forced air blower fluidizes the sand and helps in attrition also, whereas
suction blower sucks away the separated clay,Na20, Carbonates and fines.
• Piping: Piping between Reclaimer, Cyclone and Bag Filter is provided for Standard
Layout.

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TECHNICAL SPECIFICATIONS: (COLUMN 'A').
Model RSMS50 RSMS150 RSMS240 RSMS110 RSMS330 RSMS500
Capacity 50 150 240 110 330 500
Kg/Batch
Output 170-200 450-600 700-850 300-400 900-1100 1400-1600 Kg/Hr.
Installed 10 25 38 18.5 52.5 77.5
Power HP
ADVANTAGES: This system of Reclamation of Silicate Bonded Sands is more cost effective than any other method, is ecologically and environment friendly as it does not involve, the costs and the pollution caused by disposal and dumping of waste Sands and other effluents..
The advantages of COz Silicate system for smaller foundries is mainly due to its very long bench life, which permits mixed sand to be stored for long periods prior to use. The blinder addition ratio is relatively high (normally around 3.5% to 4.5%) allowing the CQ Silicate System to tolerate variations in the thoroughness of mixing. The quality of mixing equipment and level of skill required to produce acceptable quantity is low and not producing any obnoxious gases and with introduction of Bag Filter in addition to cyclone, hardly any particulate are let out to atmosphere. It is comparatively pollution free and the amount of gas formed in this process is less and is primarily water vapor, which is non-toxic to the skin
We claim :
(1) A method for reclaiming waste foundry Sand having watepsoluble organic binder
cured by CO2 gas, herein referred to as Reclamation of Waste Foundry Sand
having Water Soluble Organic Binder cured by CO2 gas. The sand used is Silica/
Olivine/ Chromite/ Zircon. And the said BINDER is Sodium Silicate of Foundry
Grade with or without collapsible agents added in various proportions.
(2) A machine for reclaiming Waste Foundry Sand referred to as Reclaimer Shell
Simplex Machine with technical specifications as laid down in Column 'A' &
drawing in Figure l;l thereof. The Reclaimer Shell Simplex Machine comprising of a
single shell and the material is received through the batch hopper through gate and the
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discharge takes place from the discharge chute and the cyclone dust separator does the primary separation of fine sand collects the dusts in the dust box wherein the Waste Foundry Moulding Sand Input can vary from grain size to lumps upto 100 mm in size in various proportions
(3) A machine for reclaiming Waste Foundry Sand referred to as Reclaimer Shell Duplex Machine with technical specifications as laid down in Column 'A* &
drawing in Figure 2 therefore. The only difference between the machines as described in para 2 above and the Duplex Machine is that in the Duplex Machine, there are twin shells. The first twin receives the material through batch hopper and the discharge takes place from the twin shell. The rest of the function of this machine is substantially similar to the Simplex Shell Machine.

Dated this 7th day of November, 2002

To
The Controller of Patents,
The Patent Office,
Mumbai.

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