— 277 — 
Guarantee 
We guarantee the design and construction of the plant quoted 
for a period of twelve months from the date of starting work, 
in so far that we undertake to replace free of charge any part or 
parts proved defective in design material or workmanship during 
the said period, ordinary wear and tear excepted. We will not be 
responsible for any liquidated or other damages whatever. 
(Signed ) Machinenbau-Anstalt Humboldt, 
DESCRIPTIONS OF COAL CRUSHING, SCREENING, WASHING AND BRIQUETT- 
ING PLANT — CAPACITY, 30 TONS PER HOUR. 
For the Brazilian Coal Commission, Rio de Janeiro 
According to the tests we have made only 33 °/, of the coal 
treated, i. e., 10 tons per hour of the n. I quality coal which is 
the one suitable for briquetting purposes, can be taken. 
In the case of Coal n. II, a yield of about 42 °/, or 12.6 tons 
per hour is obtained. 
As the dust under 1 mm. cannot be further enriched by was- 
hing, we have arranged for it to be drawn off in dry condition 
through our patent percussion screens, and mixed with the coal 
n. Il. 
In this way the washing water does not get dirty, so quickly 
and the whole process of washing is simplified and the formation 
of slime very small. 
The coal is very ingrained and dirty, and it is therefore neces- 
sary to crush same to under 6 mm. in order to secure efficient 
washing. 
We assume that the raw coal is taken in mine trucks direct 
from the pit to a height of about 8000 mm. above rail level. 
Crushing Plant 
The crude coal is dumped on to the 50 mm. perforation 
eccentric swinging screen (2) by the tippler (1). The pieces over 
50 mm. pass direct into the coal jaw breaker (3) for preliminary 
crushing. 
