ADVANCED NON-TOXIC RADIATION SHIELDING MATERIALS FROM TAILORED BRINE SLUDGE AND A PROCESS FOR THE PREPARATION THEREOF

Abstract

Conventional shielding materials are based on single material either toxic lead or barium based compounds and any matrix made therefrom contains only single phased barium based compounds, thereby posing limited radiation shielding capacity. Since brine sludge, an industrial toxic waste product, generated in chloralkali industry contains multiple compounds; there is a need to provide a process which enables the preparation of multi-phase based radiation shielding materials. In view of the above, the present invention provides advanced non-toxic radiation shielding materials utilizing tailored brine sludge and a process that enables conversion of toxic elements like chromium, zinc, copper and vanadium present in brine sludge into non-toxic shielding phases, thereby enabling to convert a toxic waste material into highly value added advanced radiation shielding materials possessing homogeneous radiation shielding matrix.

Claims

1. An advanced non-toxic radiation shielding material comprising: [a] 200 g to 600 g of brine sludge; and [b] 20 g to 60 g of sodium hexametaphosphate.

2. A process for an advanced non-toxic radiation shielding material comprising the steps of: [a] drying 200 g to 600 g of brine sludge in an air oven at a temperature of 100 to 110 C. for a period of 1 to 2 hours; [b] heating the dried brine sludge as obtained in step [a] in a furnace at a temperature ranging from 800 to 1300 C. for a period of 1 to 2 hours; [c] mechano-chemical processing of the heat treated brine sludge obtained in step [b] by grinding with 20 to 60 g of sodium hexametaphosphate in a ball mill or planetary mill for a period of 1 to 6 hours to obtain tailored brine sludge powder; and [d] compacting the tailored brine sludge powder obtained in step [c] in a steel mold using hydraulic pressure in a range of 100 to 300 kg/cm.sup.2 in the form of tiles to obtain the desired advanced non-toxic radiation shielding material.

3. The process of claim 2, wherein the dimensions of the tiles are 10 cm10 cm5-10 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0059] In the process developed in the present invention, brine sludge was dried in an air oven and was reheat treated in a furnace in the temperature range of 800 C. to 1300 C. for a period of 1 to 2 hours. The heat treated brine sludge so obtained was further mechano-chemically processed by grinding with sodium hexametaphosphate in a ball mill or planetary mill etc. for a period of 1-6 hours. The tailored brine sludge powder thus obtained was further compacted in a steel mold, using hydraulic pressure in the range of 100-300 kg/cm.sup.2 in the form of tiles of desired dimensions to make advanced non-toxic radiation shielding materials.

[0060] The process for the preparation of the aforesaid advanced non-toxic radiation shielding materials involves together drying of 200 g-600 g of brine sludge in an air oven at 100 c.-110 c. for a period of 1-2 hours followed by heating in a furnace in the temperature range of 800 C.-1300 C. for a period of 1-2 hours. The heat treated brine sludge so obtained was further mechano-chemically processed by grinding with 20 g-60 g of sodium hexametaphosphate in a ball mill or planetary mill etc. for a period of 1-6 hours and the tailored brine sludge powder so obtained was further compacted in a steel mold, using hydraulic pressure in the range of 100-300 kg/cm.sup.2 in the form of tiles of dimensions 10 cm10 cm5-10 mm to make advanced non-toxic radiation shielding materials. The characteristics of the developed materials so obtained were tested for Impact strength and water absorption and x ray attenuation test.

TABLE-US-00001 SYNERGISM DATA: The table provided here as under depicts the synergism between the components of the claimed composition. X-ray attenuation test with standard filter at respective kV using narrow beam X-ray qualities at 250 kV with (3Pb + 2Sn + 2Al) filter, 200 kV with (1Pb + 2Cu + 3Sn + 2Al), at 150 kV with (2.5Sn + 2Al), and at 100 kV With (5Cu + 2Al) Impact and the attenuation for Si. Components added [along with Strength- Water various kV i.e. at 250, no. quantities] and parameters adopted kgfm .Math. cm.sup.1 absorption 200, 150 and 100 kV 1 drying of 200 g of brine sludge in an air 0.020 16 19, 25, 50 and 70% oven at 100 C. for a period of 2 hours and respectively. followed by heating in a furnace at the temperature of 800 C. for a period of 2 hours and the heat treated brine sludge so obtained was further mechano-chemically processed by grinding with 20 g of sodium hexameta phosphate in a ball mill or planetary mill etc. for a period of 2 hours and the tailored brine sludge powder so obtained was further compacted in a steel mold, using hydraulic pressure in the range of 100 kg/cm.sup.2 in the form of tiles of dimensions 10 cm 10 cm 5 mm to make advanced radiation shielding material. 2 drying of 500 g of brine sludge in an air 0.022 14 21, 29, 55 and 75% oven at 100 C. for a period of 2 hours and respectively. followed by heating in a furnace at the temperature of 900 C. for a period of 2 hours and the heat treated brine sludge so obtained was further mechano-chemically processed by grinding with 50 g of sodium hexametaphosphate in a ball mill or planetary mill etc. for a period of 8 hours and the tailored brine sludge powder so obtained was further compacted in a steel mold, using hydraulic pressure in the range of 100 kg/cm.sup.2 in the form of tiles of dimensions 10 cm 10 cm 9 mm to make advanced radiation shielding material. 3 drying of 300 g of brine sludge in an air 0.025 12 24, 33, 60 and 80% oven at 100 C. for a period of 2 hours and respectively. followed by heating in a furnace at the temperature of 1000 C. for a period of 1 hour and the heat treated brine sludge so obtained was further mechano-chemically processed by grinding with 30 g of sodium hexametaphosphate in a ball mill or planetary mill etc. for a period of 3 hours and the tailored brine sludge powder so obtained was further compacted in a steel mold, using hydraulic pressure in the range of 100 kg/cm.sup.2 in the form of tiles of dimensions 10 cm 10 cm 5 mm to make advanced radiation shielding material. 4 drying of 400 g of brine sludge in an air 0.028 10 29, 38, 64 and 85% oven at 100 C. for a period of 2 hours and respectively. followed by heating in a furnace at the temperature of 1100 C. for a period of 1 hour and the heat treated brine sludge so obtained was further mechano-chemically processed by grinding with 40 g of sodium hexametaphosphate in a ball mill or planetary mill etc. for a period of 4 hours and the tailored brine sludge powder so obtained was further compacted in a steel mold, using hydraulic pressure in the range of 100 kg/cm.sup.2 in the form of tiles of dimensions 10 cm 10 cm 8 mm to make advanced radiation shielding material. 5 drying of 600 g of brine sludge in an air 0.030 7 34, 43, 69 and 90% oven at 100 C. for a period of 2 hours and respectively. followed by heating in a furnace at the temperature of 1300 C. for a period of 1 hour and the heat treated brine sludge so obtained was further mechano-chemically processed by grinding with 60 g of sodium hexameta phosphate in a ball mill or planetary mill etc. for a period of 6 hours and the tailored brine sludge powder so obtained was further compacted in a steel mold, using hydraulic pressure in the range of 100 kg/cm.sup.2 in the form of tiles of dimensions 10 cm 10 cm 10 mm to make advanced radiation shielding material.

EXAMPLES

[0061] The following examples are given by way of illustration and therefore should not be construed to limit the scope of the present invention in any manner.

Example 1

[0062] The process for making advanced non-toxic radiation shielding materials utilizing tailored brine sludge, comprises drying of 200 g of brine sludge in an air oven at 100 c. for a period of 2 hours followed by heating in a furnace at the temperature of 800 c. for a period of 2 hours. The heat treated brine sludge so obtained was further mechano-chemically processed by grinding with 20 g of sodium hexametaphosphate in a ball mill or planetary mill for a period of 2 hours and the tailored brine sludge powder so obtained was further compacted in a steel mold, using hydraulic pressure in the range of 100 kg/cm.sup.2 in the form of tiles of dimensions 10 cm10 cm5 mm to obtain the desired advanced radiation shielding material.

[0063] The sample so prepared having 5 mm thickness was evaluated for its X-ray attenuation test with standard filter at respective kV using narrow beam X-ray qualities at 250 kV with (3Pb+2Sn+2Al) filter, 200 kV with (1Pb+2Cu+3Sn+2Al), at 150 kV with (2.5Sn+2Al), and at 100 kV With (5Cu+2Al) and the attenuation for various kV i.e. at 250, 200, 150 and 100 kV were found to be 19, 25, 50 and 70% respectively. The impact strength of the sample was found to be 0.020 kgfm.Math.cm.sup.1 and water absorption in the range of 16.0%.

Example 2

[0064] The process for making advanced non-toxic radiation shielding materials utilizing tailored brine sludge, comprises drying of 500 g of brine sludge in an air oven at 100 c. for a period of 2 hours followed by heating in a furnace at the temperature of 900 c. for a period of 2 hours. The heat treated brine sludge so obtained was further mechano-chemically processed by grinding with 50 g of sodium hexametaphosphate in a ball mill or planetary mill for a period of 8 hours and the tailored brine sludge powder so obtained was further compacted in a steel mold, using hydraulic pressure in the range of 100 kg/cm.sup.2 in the form of tiles of dimensions 10 cm10 cm9 mm to obtain the desired advanced radiation shielding material.

[0065] The sample so prepared having 9 mm thickness was evaluated for its X-ray attenuation test with standard filter at respective kV using narrow beam X-ray qualities at 250 kV with (3Pb+2Sn+2Al) filter, 200 kV with (1Pb+2Cu+3Sn+2Al), at 150 kV with (2.5Sn+2Al), and at 100 kV With (5Cu+2Al) and the attenuation for various kV i.e. at 250, 200, 150 and 100 kV were found to be 21, 29, 55 and 75% respectively. The impact strength of the sample was found to be 0.022 kgfm.Math.cm.sup.1 and water absorption in the range of 14.0%.

Example 3

[0066] The process for making advanced non-toxic radiation shielding materials utilizing tailored brine sludge, comprises drying of 300 g of brine sludge in an air oven at 100 c. for a period of 2 hours followed by heating in a furnace at the temperature of 1000 c. for a period of 1 hour. The heat treated brine sludge so obtained was further mechano-chemically processed by grinding with 30 g of sodium hexametaphosphate in a ball mill or planetary mill for a period of 3 hours and the tailored brine sludge powder so obtained was further compacted in a steel mold, using hydraulic pressure in the range of 100 kg/cm.sup.2 in the form of tiles of dimensions 10 cm10 cm5 mm to obtain the desired advanced radiation shielding material.

[0067] The sample so prepared having 5 mm thickness was evaluated for its X-ray attenuation test with standard filter at respective kV using narrow beam X-ray qualities at 250 kV with (3Pb+2Sn+2Al) filter, 200 kV with (1Pb+2Cu+3Sn+2Al), at 150 kV with (2.5Sn+2Al), and at 100 kV With (5Cu+2Al) and the attenuation for various kV i.e. at 250, 200, 150 and 100 kV were found to be 24, 33, 60 and 80% respectively. The impact strength of the sample was found to be 0.025 kgfm.Math.cm.sup.1 and water absorption in the range of 12.0%.

Example 4

[0068] The process for making advanced non-toxic radiation shielding materials utilizing tailored brine sludge, comprises drying of 400 g of brine sludge in an air oven at 100 c. for a period of 2 hours followed by heating in a furnace at the temperature of 1100 c. for a period of 1 hour. The heat treated brine sludge so obtained was further mechano-chemically processed by grinding with 40 g of sodium hexametaphosphate in a ball mill or planetary mill for a period of 4 hours and the tailored brine sludge powder so obtained was further compacted in a steel mold, using hydraulic pressure in the range of 100 kg/cm.sup.2 in the form of tiles of dimensions 10 cm10 cm8 mm to obtain the desired advanced radiation shielding material.

[0069] The sample so prepared having 8 mm thickness was evaluated for its X-ray attenuation test with standard filter at respective kV using narrow beam X-ray qualities at 250 kV with (3Pb+2Sn+2Al) filter, 200 kV with (1Pb+2Cu+3Sn+2Al), at 150 kV with (2.5Sn+2Al), and at 100 kV With (5Cu+2Al) and the attenuation for various kV i.e. at 250, 200, 150 and 100 kV were found to be 29, 38, 64 and 85% respectively. The impact strength of the sample was found to be 0.028 kgfm.Math.cm.sup.1 and water absorption in the range of 10.0%.

Example 5

[0070] The process for making advanced non-toxic radiation shielding materials utilizing tailored brine sludge, comprises drying of 600 g of brine sludge in an air oven at 100 c. for a period of 2 hours followed by heating in a furnace at the temperature of 1300 c. for a period of 1 hour. The heat treated brine sludge so obtained was further mechano-chemically processed by grinding with 60 g of sodium hexametaphosphate in a ball mill or planetary mill for a period of 6 hours and the tailored brine sludge powder so obtained was further compacted in a steel mold, using hydraulic pressure in the range of 100 kg/cm.sup.2 in the form of tiles of dimensions 10 cm10 cm10 mm to obtain the desired advanced radiation shielding material.

[0071] The sample so prepared having 10 mm thickness was evaluated for its X-ray attenuation test with standard filter at respective kV using narrow beam X-ray qualities at 250 kV with (3Pb+2Sn+2Al) filter, 200 kV with (1Pb+2Cu+3Sn+2Al), at 150 kV with (2.5Sn+2Al), and at 100 kV With (5Cu+2Al) and the attenuation for various kV i.e. at 250, 200, 150 and 100 kV were found to be 34, 43, 69 and 90% respectively. The impact strength of the sample was found to be 0.030 kgfm.Math.cm.sup.1 and water absorption in the range of 7.0%.

ADVANTAGES OF THE INVENTION

[0072] The process involves mechano-chemical activation of heat treated brine sludge for obtaining tailored brine sludge useful for developing homogeneous advanced radiation shielding materials. [0073] Obtaining shielding phases by chemical designing and mineralogically formulating compositions based on various precursors of chemicals present in brine sludge. [0074] Developing desired mineralogical phases necessary for obtaining uniform and homogenous advanced radiation shielding materials. [0075] Conversion of toxic elements like chromium, zinc, copper and vanadium, present in brine sludge into non-toxic form and leading to development of non-toxic shielding phases. [0076] Conversion of toxic brine sludge waste material into highly value added advanced non-toxic radiation shielding materials possessing homogeneous radiation shielding matrix. [0077] Total utilization of toxic brine sludge in making non-toxic and highly value added advanced materials thereby solving the disposal problem of toxic brine sludge waste.