Practice for Measurement of the Glass Dissolution Rate Using the Single-Pass Flow-Through Test Method

2017 ◽  
Author(s):  
1999 ◽  
Vol 556 ◽  
Author(s):  
P. K. Abraitis ◽  
B. P. McGrail ◽  
D. P. Trivedi

AbstractThe dissolution rate of a simulated Magnox waste glass has been investigated in single-pass flow-through experiments designed to investigate the role of Al and Si in the dissolution process. The results indicate that both Al and Si species suppress the rate of dissolution. These effects may be modelled using a combined Al/Si affinity term in a conventional glass dissolution rate law. Aluminium species may also play an inhibitory role when present at relatively high solution activities. In Si-rich alkaline media, the concentration of aluminium is controlled to very low levels by the development of secondary aluminosilicate phases. Removal of Al by secondary phase precipitation results in dissolved Al activities below that required to reach ‘saturation’ with respect to the glass.


1995 ◽  
Vol 412 ◽  
Author(s):  
Hui Teng ◽  
D. E. Grandstaff

AbstractDissolution of powdered glass from Kilauea volcano, Hawaii (ca 51% SiO2) was studied in a fluidized-bed, flow-through reactor at room temperature in both dilute HCI and organic ligand-bearing solutions (citrate and oxalate) to determine the effects of pH and organic acids on the dissolution rate. Dissolution was non-stoichiometric in both HCI and organic solutions; however, the relative release rates of various ions and the composition of leached layers or secondary phases are fimctions of pH and organic ligand concentration and type. In HCl solutions, the minimum glass dissolution rate, as assessed from the Na leaching rate, was 7.4 × 10−12 gm cm−2 sec−1, comparable with previous results, and was virtually independent of pH. Addition of citrate and oxalate increased the non-stoichiometry of dissolution. At pH 7, the overall rate of glass dissolution decreased (by as much as 5 times) at low ligand concentrations (< 1 mM), but increased by as much as five times at higher concentration (3 mM). High ligand concentrations do increase the release rate of some elements, especially multivalent cations, such as Fe3+ which form strong organic complexes, by as much as 100 times.


2009 ◽  
Vol 1193 ◽  
Author(s):  
H. Makigaki ◽  
Y. Inagaki ◽  
K. Idemitsu ◽  
T. Arima ◽  
S. Mitsui ◽  
...  

AbstractWe applied a new type of flow-through test method using micro-reactor consisting of a simple test apparatus with compact size to measurement of the dissolution rate of a Japanese type of simulated waste glass (P0798 glass). In this test method, a solution flows through a micro-channel (20 mm length, 2 mm width, 0.16 mm depth) in contact with a face of coupon shaped glass specimen, and the output solution is retrieved at certain intervals to be analyzed for determination of the glass dissolution rate. By using this test method the initial dissolution rate of glass matrix or forward dissolution rate was measured as a function of pH (3 to 11) and temperature (25°C to 90°C). The present test results indicated that the initial dissolution rate has ‘V-shaped’ pH dependence, and the effect of pH on the dissolution rate decreases with increase in temperature similar to the results measured by using the Single-pass flow-through (SPFT) method. The present test results also indicated that the dissolution of B is controlled by diffusion process and that of Si is controlled by surface reaction process.


2009 ◽  
Vol 1193 ◽  
Author(s):  
Y. Inagaki ◽  
S. Mitsui ◽  
H. Makigaki ◽  
K. Idemitsu ◽  
T. Arima ◽  
...  

AbstractA new type of flow-through test method using micro-reactor was developed and applied to measurement of the dissolution/alteration kinetics for a Japanese type of simulated HLW glass, P0798. In this test method, a face of coupon shaped glass specimen (30mm × 10mm × 4mm size) is in contact with a micro-channel (20mm length, 2mm width, 0.16mm depth) constructed on a PTFE (Teflon®) plate, and a solution is injected into the inlet of micro-channel at a constant rate. The injected solution, which flows through the micro-channel reacting with the glass to the outlet, is retrieved at certain intervals to be analyzed for determination of the glass dissolution/alteration rate. After the test, the glass specimen removed from the micro-reactor is subjected to surface analyses. This test method has major features as follows, 1) any controlled solution condition can be provided over the test duration, 2) a relatively high S/V ratio can be provided by use of micro-reactor in spite of using coupon shaped glass specimen, which results in precise and consistent analyses of both the solution and the reacted glass surface, 3) the test apparatus is simple with compact size and easy operation, which allows a flexible setup of test conditions. By use of this test method the dissolution/alteration rate for P0798 glass was measured as a function of pH, temperature, and time, and the results indicated that this test method is applicable and suitable for evaluation of the dissolution/alteration kinetics.


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