CONTENTS. ix 



PAGES. 



ing the raw phosphate — Crushers— Edge runners— Flatstoue mills — 

 Ball mill — Pfeiffer's mill, with combined air separator—Jaw-breaker 

 mills— Crac-king mills— Toothed roller mills— Disintegrators— Mills 

 with percussion blades fitted in circular revolving boss — Elevators 

 —Sieves— Filter press— Mixing of the phosphate with sulphuric acid 

 — Evacuation of the toxic fumes ------ 81-110 



CHAPTER VII. 



CRUSHING, SIFTING, DRYING, AND STORING OF SUPER- 

 PHOSPHATE. RETROGRADATION. 



Emptying and shifting the superphosphate house or den — New methods- 

 for the mechanical extraction of superphosphate from the " den " — 

 AUegri's plant for shifting superphosphate from the "dens ' — Break- 

 ing up and sifting or screening of superphosphate — Carr's disin- 

 tegra:or— Cvlindrical crusher fitted with teeth — Cylindrical crusher,, 

 with two rolls fitted with teeth— Artificial drying of superphosphate 

 —Theoretical review of drying— Moller and Pfeiffer's drying machine 

 — Heymann and Nitsch's process for drying superphosphates — Dr. 

 Lorenz' process- Dr. Lutjens' successor — Superheated superphos- 

 phates — Drying superphosphates in the cold — Drying of the super- 

 phosphate by dusting and mixing in the Georges crusher-sifter — 

 Storing (preservation) of superphosphate — Retrogradation (reaction) 

 of phosphoric acid — Forestalling retrogradation by Schucht's 

 method - - - - HM-i^i 



CHAPTER VIII. 



COMPOUND MANURES. 



Superphosphate of ammonia — Ammoniated superphosphate — Super- 

 phosphate of ammonia and potash— Nitrophosphate— Tables for the ^ 

 calculation of " superphosphate of ammonia "'- Dry mixings - 142-150 



CHAPTER IX. 



THE MANUFACTURE OF PHOSPHORIC ACID, DOUBLE SUPER- 

 PHOSPHATES AND VARIOUS PRODUCTS. 



Historical review — Manufacture of phosphoric acid — Manufacture of 

 double supeiphosphate— Manufacture ot superphosphate of potas- 

 sium and ammonium — Manufacture of sulpho-phosphates — Bisul- 

 phate SHperphosphate — Phosphatic peat ----- 151-1 6& 



APPENDIX. 



THK MANUFACrrRE OF PHOSPHORUS IN THE ELECTRIC FURNACE. 



Wing's process— Readman's patent— Harding's process— Gibb's furnace 

 —Irvine's furnace— Duncan's patent— Parker's patent— Landis' 

 method - 167-17^ 



