The system: calcium oxalate - sulphuric acid

The manufacture of oxalic acid includes as one of the steps in the process, the conversion of calcium oxalate to the desired oxalic acid by treatment with sulphuric acid, and the subsequent crystalization [sic] of the oxalic acid from the solution of it thus made. This investigation has dealt with this conversion step, with regard to the various factors affecting it. The effect of time, acid concentration, temperature, volume of solution, solubility of reaction products, and possible compound formation have all been considered, and from the information thus gained the conclusion has been drawn --Introduction, page 1