Swamp ore - is a type of brown iron ore ( limonite ), naturally deposited in swamps on the rhizomes of swamp plants. According to morphological features, among the limonite ores , oolitic (different sizes), cortical, spongy, and coin ores are distinguished. Oolitic ores consist of small spherical, rounded nodules - oolites. Oolitic ores are divided into bean (1–2 cm), pea (0.3–1 cm), shot (0.1–0.3 cm), and powder (up to 0.1 cm) ores in size. ocherous, sometimes porous-tuff-like with prints of plants.
Swamp ores contain 20-60% iron oxide, as well as some amounts of iron oxide, manganese oxide, water (up to 30%), silicic acid in the form of silicates, an admixture of sand, organic matter, phosphoric acid (up to 8%). Due to impurities, swamp ores are considered to be of low quality and unsuitable for modern industry.
Lake and sod or meadow ores, which are found in the form of porous nodule deposits at the bottom of lakes and in riverine or semi-bog meadows , are very close to bog ore.
Historical Significance
Initially, swamp and lake ore was used for the production of iron in critical yards and billets, which was the basis of metallurgy in Russia until the beginning of the 18th century.
The reduction of iron (liberation from oxygen) from bog and lake ores begins at a temperature of 400 ° C, and so-called sponge iron is obtained at 700–800 ° C. Special furnace stoves - billets - contained 1.5-2 pounds of ore. In ancient times, they were made in elevated places to use the power of the wind to enhance combustion. Later they learned to use artificial blasting, began to maintain fire with the help of bellows. After the iron is boiled in the batch, it is as if the “foam” is removed from it, that is, the batter is broken, a hot scream is taken from it, put on the anvil and forged: during reforging, excess slag is removed from the iron. It turns out soft, that is, cough iron, the further processing of which gave steel. Domnica for 1 season usually smelted from 75 to 150 pounds of iron.
Under Emperor Peter I , a new stage begins in the development of the Russian iron and steel industry. Water-producing plants using two-stage production are being built. Cast iron is smelted in blast furnaces, and then iron is smelted from cast iron in pudding furnaces. However, most plants continue to use swamp and lake ores, in particular, the Olonets factories. And only with the beginning of the development of the Ural iron ore, swamp and lake iron fade into the background. And soon its industrial use ceased altogether.
See also
- Lake ore
Literature
- Levinson-Lessing F. Yu. Swamp ore // Brockhaus and Efron Encyclopedic Dictionary : in 86 volumes (82 volumes and 4 additional). - SPb. , 1890-1907.