First, the toxicity of vanadium
The toxicity of vanadium is closely related to its valence and water solubility. High-valence vanadium is easily soluble in water and is highly toxic. Atmospheric vanadium compounds have a stimulating effect on the skin and respiratory tract. Long-term exposure to V 2 O 5 dust and V 2 O 5 thick environment can cause respiratory irritation accompanied by mucus production, bronchitis, chest pain, dermatitis and the like.
Second, the environmental safety indicators of vanadium
For a place where 8 hours of work per day and 40 hours of work per week, the upper limit of vanadium-containing dust is 0.5 mg/m3, and the upper limit of fine dust environment should be 0.05 mg/m3. The upper limit for short-term workers is 1.5 mg/m3. The toxicity of vanadium compounds is listed in Table 1.
Table 1 Toxicity of vanadium compounds
Oral and lethal dose of kilograms of body weight
LD 50 (14d)/mg
Inhaled lethal dose
LD 50 (14d) / (mg Â· L - 1 )
Kilogram weight epidermal lethal dose
LD 50 (14d)/mg
Analytical pure V 2 O 5
Industrial pure V 2 O 5
From a biological point of view, vanadium is a very important element. It is known that vanadium contributes to the function of biological nitrogen fixation. Due to the discovery of vanadium halide peroxidase in seaweed, it has ignited a boom in its research. Because it can form an intermediate of enzyme-vanadium hydrochloride, vanadate is The cells are easily reduced to a tetravalent state and exist as VO 2 + . In the extracellular, animal body fluids, it is easily oxidized by air to pentavalent, and exists as VO 3 - . Vanadium in the cell can promote the phosphorylation and de-phosphorylation of cellular process, control the activity of many enzymes, and participate in the regeneration of free radicals.
It is believed that vanadium has an anticancer effect in the body. Studies have shown that glutathione S-transferase (CST) is a detoxification enzyme for cancer. In the screening of trace element feeding experiments, drinking water containing NH 4 VO 3 in the mucosa of the liver and kidney of the test mouse, It was found that the activities of glutathione and CST were significantly improved, and thus vanadium was considered to have an anticancer effect.
"Gravity Die Casting. A permanent mould casting process, where the molten metal is poured from a vessle of ladle into the mould, and cavity fills with no force other than gravity, in a similar manner to the production of sand castings, although filling cn be controlled by tilting the die."
Sometimes referred to as Permanent Mould, GDC is a repeatable casting process used for non-ferrous alloy parts, typically aluminium, Zinc and Copper Base alloys.
The process differs from HPDC in that Gravity- rather than high pressure- is used to fill the mould with the liquid alloy.
GDC is suited to medium to high volumes products and typically parts are of a heavier sections than HPDC, but thinner sections than sand casting.
There are three key stages in the process.
Gravity Casting Parts,Aluminum Alloy Gravity Casting Parts,Aluminum Gravity Die Casting Parts,Gravity Casting Aluminum Parts
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