3 results about "Thorium nitrate" patented technology

The invention relates to a method for solidifying an aqueous solution of thorium nitrate Th(NO3)4, which method comprises the steps of: a) concentrating the aqueous solution by circulating the aqueous solution in an evaporator comprising an inlet for feeding the aqueous solution into the evaporator and an outlet for discharging the aqueous solution from the evaporator, wherein a temperature gradient prevails from a temperature θ1 of between 50°C and 70°C at the inlet of the evaporator to a temperature θ2 of between 130°C and 160°C at the outlet of the evaporator, whereby a concentration gradient of the aqueous solution is established between the inlet and the outlet of the evaporator, the establishment of the concentration gradient leading to a concentrated aqueous solution of thorium nitrate pentahydrate of formula Th(NO3)4.5H2O at the outlet of the evaporator; then b) transferring the thus-concentrated aqueous solution from the outlet of the evaporator to a container in which the aqueous solution is left to cool, whereby the aqueous solution solidifies in the container by crystallization of thorium nitrate pentahydrate. The invention can be used for the storage of aqueous solutions of thorium nitrate in solid form pending subsequent recovery of these solutions.

A method for extracting high-purity lead 212 based on a decay chain of thorium nitrate comprises the following steps: (1) a step of removing Pb by using a package: enabling a preliminarily filtered thorium nitrate solution to flow through a silica gel column A to adsorb and enrich Pb in the thorium nitrate solution so as to obtain a solution A; (2) preliminary purification: enabling the solution A to flow through a diatomite filter column, and adsorbing and enriching Th and Ra to obtain a solution B; (3) secondary purification: filling a DTPA modified silica gel column B with the solution flow B, and adsorbing and enriching 212Bi to obtain a solution C; (4) re-purification: taking a sulfydryl modified silica gel column C, enriching and intercepting 212Pb, and flowing out waste liquid; (5) elution and re-enrichment: eluting 212Pb on the silica gel column C by hydrochloric acid to obtain an eluent C, and enabling the eluent C to flow through a filling AG1-X8 resin column; and (6) leaching: leaching the enriched resin column by using a diammonium hydrogen citrate solution to obtain a final solution.

An apparatus and method for continuously preparing Pb-212 solution using thorium nitrate. The apparatus includes a thorium nitrate solution bottle, a first Pb-212 solution bottle, a second Pb-212 solution bottle, an air pump, a first electromagnetic three-way valve, a second electromagnetic three-way valve, a third electromagnetic three-way valve, a pressure relief valve, a spray head, a water pump, a dilute nitric acid solution bottle, and hoses. The thorium nitrate solution bottle is connected to the first and second Pb-212 solution bottles via hoses to form an airflow circulation loop under the action of the air pump, the first electromagnetic three-way valve, and the second electromagnetic three-way valve. The dilute nitric acid solution bottle is connected to the first and second Pb-212 solution bottles via hoses under the action of the water pump and the third electromagnetic three-way valve. The air pump and electromagnetic three-way valves are configured to deliver high-concentration Rn-220 from the thorium nitrate solution bottle into the first and second Pb-212 solution bottles at regular intervals, and the water pump is configured to continuously pump dilute nitric acid into the first and second Pb-212 solution bottles to continuously prepare the Pb-212 solution. The device of this invention has a simple structure and is easy to set up. It is inexpensive and environmentally friendly, and enables the continuous preparation of Pb-212 solution, which has great market application prospects.