1994 Fiscal Year Final Research Report Summary
Magnetic Separation of Alkali-and Alkaline Earth-lon Groups from a Simulated HLLW
Grant-in-Aid for General Scientific Research (C)
|Allocation Type||Single-year Grants |
|Research Institution||Osaka University |
YANAGI Tadashi Osaka Univ.Nucl, Eng., Associate Prof., 工学部, 助教授 (60029048)
UNO Masami Osaka Univ.Nucl.Eng., Assistant, 工学部, 助手 (00232885)
|Project Period (FY)
1993 – 1994
|Keywords||magnetic separation / group partitioning / high level liquid waste / cesium / strontium / ferrite seeding / carbonate precipitation / ferric ion flocculant|
On the electromagnetic separation technique, through which the components of a high level liquid waste are partitioned into four gruops with the aid of iron ferrite additives, the following matters have experimentally been examined ;
(1) The selection of an effective packing material in an electromagnetic separation column,
(2) The effect of coprecipitant and flocculant on the recovery of precipitates of alkaline earth carbonates from the solution, and
(3) The scheme by which strontium and cesium ions are recovered at high percentage from a simulated high level liquid nuclear waste.
The sample solution was prepared by denitration with formic acid to pH=1 of 2.5M nitric acid solution of a simulated high level liquid waste, and by centrifugation to remove precipitates formed.
(1) Selection of packing material ;
Three types of stainless steels were tested : (a) sus-410 net (0.1mm wire dia., 1*2mm mesh width), (b) -440 ball (6mm dia.) and (c) -434 coiled ribbon (0.1mm thick., 0.5mm width). Among
these steel (c) was preferable to others on the durability to nitric acid and on the trapping efficiency of ferrite particulates from solution. This is probably due to the great contribution of a high gradient magnetic field generated at ribbon edges in the column.
(2) Coprecipitant and flocculant ;
Cadmium ion and ferric ion were chosen as a coprecipitant and a flocculant, respectively. The former showed no effect in the Strontium carbonate precipitation, but the latter greatly contributed to strontium recovery at higher percentage than 97%, without decreasing high recovery of cesium.
(3) Separatio scheme ;
From the results, the operation shceme was proposed as one which included the carbonate formation, combined with the ferric ion flocculant as well as with iron ferrite additive. The scheme proved effective in mutual separation and recovery of cesium and strontium ions from a simulated high level liquid waste at prcentage higher than 97%, using an electromagnetic filtration column packed with coiled ribbons of sus-434. Less
Research Products (2 results)