1918.] The N.Z. Journal of Science and Technology. 
381 
The Alunite Deposits of Australia and their Utilization, by F. W. James, 
Bulletin No . 3, Advisory Council of Science and Industry, 38 pp., 9 plates ; 
Melbourne, 1917. 
This is a report by Mr. Frank W. James of certain investigations con¬ 
ducted by him under the direction of a special committee of the Advisory 
Council. The importance of potash fertilizers is emphasized, especially 
in the growing of the sugar-cane, and of beets, sorghum, potatoes, onions, 
and maize ; and attention is directed to the serious shortage, owing to the 
war, of potash salts suitable for this purpose—which were chiefly derived 
before from the Stassfurt chloride deposits in Germany. After naming 
the chief foreign localities where alunite is found, the writer refers to the 
Australian occurrences of the mineral—namely, at Bullahdelah, New South 
Wales, where there is a large supply of ore, much of it not of very high 
grade (the best having been shipped since 1891 to England and used for 
the manufacture of alum), and at Carricklinga Head and Warnertown, in 
South Australia, the ore at these two places being as yet undetermined in 
quantity, but at the former at least of good quality. In Italy alunite las 
been used as a source of alum since the fifteenth century, and the La Tolfa 
process of extraction gives the key to Mr. James’s researches and results ; 
that process consists in the roasting of the ore to a dull-red heat—that is, 
until a temperature of about 500° C. is reached. Alunite, which is a 
hydrated basic sulphate of potassium and aluminium, breaks up under the 
treatment into alum and insoluble alumina. Mr. James, whose contri¬ 
bution is most precise and valuable (especially in regard to the temperatures 
at which different changes occur), finds that as soon as a much higher 
temperature than 500° C. is reached the alum is resolved into potassium 
sulphate, pure alumina (or other insoluble alumina product), and sulphuric 
anhydride. It is showm that the best temperature from the point of view 
of economy and efficiency is a temperature near, but not much above, 
1,000° C. ; the process is described in detail as it would be worked on 
a manufacturing scale. The by-products could be utilized, the alumina 
products being treated by the Bayer (caustic soda) process for the 
extraction of aluminium, and the sulphur oxides being used for the making 
of sulphuric acid. 
The production of potassium sulphate is not the only way of utilizing 
the alunite as a fertilizing agent; a firm in South Australia is already selling 
a lime fertilizer formed by roasting a small quantity of alunite with the 
limestone in the kiln, and Mr. James points out that there is no reason why 
a much higher grade potash product should not be produced in the same 
way. Moreover, experiments conducted by the Bureau of Soils, Washing¬ 
ton, U.S.A. ( Circular No. 76) have shown that the increase of crop from 
the use of roasted alunite was even greater than when potassium sulphate 
or chloride was used. 
For biological and other sources of potash readers may be referred to 
Bulletin No. 2 of the Department of Chemistry, South Australia (reviewed 
in the March number of this Journal), and particularly to four articles on 
“ Potash in Agriculture,” by Mr. B. C. Aston, which cover most of the 
ground ( Journal of Agriculture, July, 1915 ; December, 1916 ; June, 1917 ; 
May, 1918). This by the way. 
The present bulletin is completed by appendices containing reports 
by the Government geologists of the alunite deposits, and very full tables 
of the experiments ; although it is not the last word on the subject (for the 
