- THE MONNIER PROCESS OF REDUCING ORES. 329 



This valuable mine is owned by Messrs.Walrathg and Hunter. During the 

 last six months they have been preparing for the introduction on this coast 

 of this new method of reducing ores, and for more than a week past their 

 works have been in successful operation. This is the method of reducing 

 refractory ores by roasting and lixiviation, as invented and patented by 

 Alfred Monnier. 



Being kindly afforded every facility to investigate this method of extract- 

 ing the precious metals so entirely new to our coast, I shall try, by aid of 

 the Professor's explanations, and the accompanying diagram I have made of 

 the ground plan of the works, to give your readers some idea what this 

 method is, how it differs from, and what its advantages are over the usual 

 method. 



These works are on a steep hillside. Going from A, the highest pointy 

 to B, the lowest, you descend from floor to floor some 20 feet. The shaft 

 and hoisting works are about 100 feet to left of point 1. The order of ar- 

 rangement of cylinder, tanks, arastras, etc., will naturally vary according; 

 to the surface to be built upon. 



1. Lump ore from mine. S. Sulphate of Soda. 2. Eock-breaker and 

 crusher. 3. Elevators which carry crushed ore and soda to 4, receptacle- 

 of same, whence, through 5, they are conducted into 6, revolving cylinder, 

 where the mixture is roasted. 7. Fire-box of cylinder. 8. Lixiviating 

 tanks. 9. Eeservoir for lixiviating tanks. 10. Eeservoir for strong solu- 

 tion. 11. Feeder for evaporator. 12, Evaporator. 13. Crystallizing tank. 

 14. Arastras. 15, Feeder for copper-plate in 16, amalgamating trough. P. 

 Eoasted and lixiviating ore ready for arastras, S2. Sulphate of soda taken 

 from crystallizing tank, b, point where iron car receives roasted ore. t,. 

 tramway over which car passes to lixiviators. 



What are known among miners as "refractory ores," are those contain- 

 ing a large proportion of metallic sulphurets. The method long in vogue in 

 what are called the "sulphuret works" of our mining regions, is that of c/iZo- 

 rination, where common salt, manganese, and sulphuric acid are used, and 

 must be purchased for that purpose. The Monnier method for the treat- 

 ment of metallic sulphurets may be correctly distinguished from the former 

 as the method of siclphatization — -a term suggested by Prof. Monnier — since 

 its chemical processes consist in changing into sulphates the sulphurets of 

 different metals contained in the quartzose ore. 



The Messrs. Walraths and Hunter have been working their mine about 

 six years, reducing the ore by the common method of chlorination. Their 

 shaft is down something more than 800 feet, with the usual drifts every 100' 

 feet. Some twenty men are now at work in the different drifts, and the ore 

 brought up daily is a very fine quality of sulphurets. The chemical com- 

 pounds it contains, besides the pure silica of the quartz, are sulphurets of 

 silver, copper, iron, zinc and lead, containing gold, also small quantities of 

 arsenic and antimony. That portion of the ore which is reduced by the 

 Monnier method is treated as follows : 



