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52
THE MINERAL WEALTH OF BRAZIL
lhe
state of São Paulo in September 1939 has added materially to the
economic development of the ores of that region, especially those of
silver and lead.
In
Pandeiros which is 36 kilometers from the city of Januaria in the state
of Minas Gerais, silver is found associated with zinc. It is an
interesting vein of willmenite which is being worked by the! Cia.
Jamiarense de Explorações Ltda.
Various
analyses of the mineral of Januaria have been made in Rio de Janeiro
and in Belo Horizonte in the state of Minas Gerais and have showed
varying metallic silver contents up to 32%.
The
higher silver content ores are found only in the surface deposits while
in the other deeper ores which have not been concentrated, the ratio of
silver continues to remain from 0.5% to 1.5%. that is, 5 to 15 kilograms of silver per ton of ore.
SILVER
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Production
of this precious metal in Brazil has shown little if any pro-gress
until 1934, the output in that year amounting to 582 kilograms, to 648
kilograms in 1935, to 785 kilograms in 1937, to 794 kilograms in 1938,
to 842 kilograms in 1939 and 768 kilograms in 1940.
Compared
to the irregular production is that of importation which has varied
still more sharply over the years manifesting an abnormal increase in
the last three years, that of 1940 being 5,772 kilograms the highest in
the import history of this metal. In the 1920-9 decade, imports of this
metal averaged 519 kilograms annually and increased to 733 kilograms in
the 1930-4 quinquennium: the average for the 1935-9 period was 1,645
kilograms. The principal source of| this metal up to the War was
England while the United States and Germany were secondarily important.
In 1940, the principal source was the United States.
The
import price of silver (CIF Brazil) has varied as follows: 1938 — 275
milreis per gram, 1939 — 272 milreis and 251 milreis in 1940. The
average mine price in 1940 was 200 milreis.
15. MANGANESE
It
is estimated that about 95% of the world production of manganese ore is
absorbed by the iron and steel industry, principally in the manufacture
of
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