Patent Application
20070098607
The present invention relates to a method for recycling; more particularly relates to recycling Thallium(Tl)-203 isotope from a remnant electroplating solution of Tl-203 target or a remnant chemical Tl-201 solution with a recycling rate over 98% to be made into an electroplating solution or a solid thallous oxide used in nuclear medicine.
A prior art, “Tumor Imaging Agent of Gallium Dimercaptosuccinate”, is proclaimed in Taiwan, where a gallium(Ga)-67 dimercaptosuccinate compound having a dimercaptosuccinic acid labeled with Ga-67 radioisotope is obtained by a reaction of a radioactive 67GaCl and a dimercaptosuccinic acid to be a tumor imaging agent. Nevertheless, a radioisotope is hard to obtain so that the price is high. And, the recycling of the radioisotope with the purification is done with high cost. Hence, the prior art does not fulfill users' requests on actual use.
The main purpose of the present invention is to provide a method for recycling Tl-203 isotope with high purity and high recycling rate from a remnant solution of Tl-201 radioisotope.
To achieve the above purpose, the present invention is a method for recycling Tl-203 isotope in a remnant solution of Tl-201 radioisotope, where, through a chemical precipitation, an amount of Tl-203 precipitates is obtained in a remnant electroplating solution of Tl-203 target or a remnant chemical Tl-201 solution; the precipitates having Tl-203 are collected and rinsed to obtain Tl-203 isotopes; and, the Tl-203 isotopes are dissolved in a sulphuric acid to obtain a target electroplating solution or are heated to 900° C. to obtain a solid Tl-203 oxide for easy storage. The present invention achieves a recycling rate over 98% and the chemical process flow is simple and convenient with high purity and high recycling rate through chemical precipitation and ion exchange; so, the present invention is used in an automatic or semi-automatic process to improve the convenience and the repetition of the recycling to save time and human resources. Accordingly, a novel method for recycling Tl-203 isotope in a remnant solution of Tl-201 radioisotope is obtained.
The present invention will be better understood from the following detailed descriptions of the preferred embodiments according to the present invention, taken in conjunction with the accompanying drawings, in which
The following descriptions of the preferred embodiments are provided to understand the features and the structures of the present invention.
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Thus, a novel method for recycling Tl-203 isotope in a remnant solution of Tl-201 radioisotope is obtained. For further understanding the present invention, some preferred embodiments are described as follows:
Recycling Tl-203 isotopes from remnant electroplating solutions of Tl-203 targets
Please refer to
An ion exchange [12] is processed through the remnant electroplating solution of Tl-203 target [11] by using a 1 cm φ×10 cm L ion-exchange tube for H2SO4-form cation exchange resin and a SJ-1211H rolling motor of ATTO Corp., Japan to remove the organic solvent and absorb the Tl-203. After the ion exchange [12], Tl-203 is washed down [13] by using a 4N sulphuric acid to obtain a Tl-203 solution. A pH value of the Tl-203 solution is then adjusted [14] by using a NaOH solution to obtain a Tl-203 solution with a pH value of 12, where the pH value after the adjusting [14] lies between 12 and 13.5. The Tl-203 solution with a pH value of 12 is added with a saturated sulfide solution to be precipitated [15]. After being totally precipitated, the Tl-203 solution is stayed steady for 1 hour to obtain a solution having black precipitate of thallous sulfide. The Tl-203 solution is then moved into a semi-automatic vacuating filtration system, whose filtrating tank is of funnel-type made by KIMAX Corp. and whose filter plate is of elaborate-type with 4˜5.5 mm (millimeter) apertures, to be filtrated [16] to separate a precipitate out of a recycled solution. The recycled solution is poured into a wastes bucket, which can be circularly recycled for at least 20 times. The precipitate and the surfaces of the filtrating tank is rinsed [17] by using a NaOH solution and a distilled water to obtain a Tl-203 isotopes [18]. The solution after the rinsing is collected to be recycled, whose recycling rate is at least 97% and whose actual recycling rate is over 98%. For easy storage, the Tl-203 isotope [18] is heated to 900° C. to obtain a solid thallous oxide, or is dissolved in a sulphuric acid to obtain a target electroplating solution through diluting and evaporating.
Recycling Tl-203 isotopes from remnant chemical Tl-201 solutions
Please refer to
A pH value of the remnant chemical Tl-201 isolation solution [21] is adjusted [22] with a NaOH solution to obtain a Tl-201 solution having a pH value of 12, where the pH value after the adjusting [22] lies between 12 and 13.5. The Tl-203 solution is then added with a saturated sulfide solution to be precipitated [23]. After being totally precipitated, the Tl-203 solution is stayed steady for 1 hour to obtain a solution having a black precipitate of thallous sulfide. The Tl-203 solution is then moved into a semi-automatic vacuating filtration system, whose filtrating tank is of funnel-type made by KIMAX Corp. and whose filter plate is of elaborate-type with 4˜5.5 mm (millimeter) apertures, to be filtrated [24] to separate a precipitate out of a recycled solution. The recycled solution is poured into a wastes bucket, which can be circularly recycled for at least 20 times. The precipitate and the surfaces of the filtrating tank is rinsed [25] by using a NaOH solution and a distilled water to obtain Tl-203 isotopes [26]. The solution after the rinsing is collected to be recycled, whose recycling rate is at least 97% and whose actual recycling rate is over 98%. For easy storage, the Tl-203 isotope [26] is heated to 900° C. to obtain a solid thallous oxide, or is dissolved in a sulphuric acid to obtain a target electroplating solution through diluting and evaporating.
An application of electroplating solutions of TL-203 target recycled from Example 1 and Example 2
Electroplating solutions of TL-203 target recycled from Example 1 and Example 2 are loaded in an electroplating tank. The electroplating solution of TL-203 target is processed through an electroplating on an irradiation target of a cyclotron having a copper bottom and a silver surface. The irradiation target of the cyclotron is transported to an irradiation station of the cyclotron to be irradiated with protons of 29 MeV and 200 μA. After an accumulation of 1500 μAh through the irradiation, the irradiation target of the cyclotron is transported to a lead chamber for a chemical separation and purification. The Pb-201 isotope obtained after the nuclear reaction is deposited and is stayed steady for 32 hours to obtain Tl-201 with high-purity and high-quality from the Pb-201 solution through the separation and purification. With a quality control to conform to nuclear-medicine quality, the Tl-201 is made into an injection of 201TlCl to be used in a single photon emission computed tomography (SPECT) or a myocardium diagnosis.
An application of solid 203 thallous oxide recycled from Example 1 and Example 2
The solid thallous-203 oxide recycled from Example 1 and Example 2 is dissolved in a sulphuric acid to obtain a Tl-203 electroplating solution and is loaded in an electroplating tank. The TL-203 electroplating solution is processed through an electroplating on an irradiation target of a cyclotron having a copper bottom and a silver surface. The irradiation target of the cyclotron is transported to an irradiation station of the cyclotron to be irradiated with protons of 29 MeV and 200 μA . After an accumulation of 1500 μAh through the irradiation, the irradiation target of the cyclotron is transported to a lead chamber for chemical separation and purification. The Pb-201 isotope obtained after the nuclear reaction is deposited and is stayed steady for 32 hours to obtain Tl-201 with high-purity and high-quality from the Pb-201 solution through the separation and purification. With a quality control to conform to nuclear-medicine quality, the Tl-201 is made into an injection of 201TlCl to be used in a SPECT or a myocardium diagnosis.
The raw materials recycled from the remnant of target electroplating solution or chemical solution and the injections made with the raw materials are examined and are all passed as shown in
The preferred embodiments herein disclosed are not intended to unnecessarily limit the scope of the invention. Therefore, simple modifications or variations belonging to the equivalent of the scope of the claims and the instructions disclosed herein for a patent are all within the scope of the present invention.
