Why are there quality differences in trace elements in the feed industry?
1. Differences in industry demand
Nearly all the trace element producers are chemical enterprises, and the same product can be sold to multiple industries. For example, copper sulfate products can be used in many industries such as feed additives, fertilizers, fungicides, mordants, copper electroplating, and ore dressing;
However, different industries have completely different quality requirements for products, and product prices also vary significantly.
2. Ore (raw material) sources are different
Some trace elements (copper, iron, zinc and cobalt) are extracted from industrial waste, wastewater or industrial by-products.
Different sources of raw materials contain different impurities, resulting in different final product quality. Some trace elements (manganese, magnesium, potassium medical stone) are extracted from ores or salt lakes.
Different ore sources or different grades of raw ores result in different final product quality.
3. National standards are not comprehensive
At present, there are no national standards for some trace element products.
National standards only set requirements for main contents and sanitary indicators (arsenic, lead, cadmium and mercury), but do not have clear requirements for impurities that affect product quality.
National standards are only the basic threshold for product quality. Therefore, different feed companies (foreign-funded enterprises, nationwide enterprises, local leading enterprises, small and medium-sized enterprises) have put forward different quality requirements based on the national standards for trace elements.
Even some small and medium-sized enterprises only look at the appearance without conducting any testing when purchasing trace elements.
Which trace elements in the feed industry have national standards?
Products with national standard products (9 products) Copper sulfate, basic cupric chloride, ferrous sulfate, zinc sulfate, zinc oxide, manganese sulfate, magnesium sulfate, calcium iodate, sodium selenite
National standards clearly define indicators: main content and health indicators (arsenic, lead, cadmium, mercury)
Products without national standards (5 products) Magnesium oxide, potassium iodide, cobalt chloride, calcium formate, potassium chloride
Differences in the quality of trace element products: copper sulfate
Copper sulfate: extracted from etching waste liquid of circuit boards. The product has national standards, which has clearly indicated the requirements for main content and hygiene indicators.
Sustar products (in addition to meeting the national standards):
Raw material acidity control ≤0.014%: High-acid products produce pungent odors, reduce product fluidity, easily absorb moisture and agglomerate, accelerate the discoloration of premixes, are more likely to destroy vitamins and enzyme preparations, and are more likely to cause oil deterioration.
Copper sand is in the form of blue crystalline particles, and the appearance of copper sand can be used to preliminarily judge the purity of the product.
Silicon dioxide is added to copper powder as anti-caking
Products available on the market:
The acidity of copper sulfate products can reach up to 0.03%. Sustar company defines products with acidity exceeding 0.02% as high-acid products.
The etching fluid of small-scale electronics factories may contain a large amount of organic matter, and the risk of dioxin is relatively high. Sand copper contains impurity iron elements, and the product turns yellow in appearance after heating. The appearance of sand copper appears green or white. If the temperature fluctuates greatly during the drying process, the color may change from blue to white.
Sand copper has no crystalline, needle-shaped or flaky crystals and is easy to agglomerate.
The copper powder and the carrier are not mixed evenly, and the content fluctuates greatly; if the carrier is added excessively, the content is unqualified.
The particle size of copper powder is uneven, and the proportion of oversize product of 40-mesh sieve is relatively high.
After dissolving in water, the solution contains obvious water-insoluble matter, suspended matter and floating matter.
Differences in the quality of trace element products: Basic copper chloride
Basic copper chloride has the same source as copper sulfate, and the product is extracted from etching waste liquid from circuit boards. The product has national standards, which has clearly indicated the requirements for main content and hygiene indicators.
Sustar products (in addition to meeting the national standards):
Uniform color, no lumping, good fluidity.
Control nitrogen and free chlorine indicators (0.14%; 0.1%) to reduce dioxin risks and agglomeration.
Products available on the market:
The main content is unqualified.
There is big color difference among products in the same batch.
Obvious white spots.
Powder, poor fluidity
With visible impurities.
High in nitrogen and free chlorine, prone to agglomeration.
Differences in the quality of trace element products: ferrous sulfate
Ferrous sulfate is a by-product of titanium dioxide in the chemical industry. The product has national standards, which has clearly indicated the requirements for main content and hygiene indicators.
Sustar products (in addition to meeting the national standards):
Uniform color, no lumping.
Good fluidity.
Trivalent iron is within 0.15%.
Products available on the market:
The trivalent iron is unqualified and the main content is unqualified.
There is big color difference among products in the same batch.
The moisture content is high.
The fineness does not meet national standards.
A small amount of dust removal material.
The fluidity is poor, the fineness is fine, and it is easy to clump.
There is a dry process for producing ferrous iron, and the product has extremely high acidity.
The high valent iron content has a great impact on the quality of the premix feed.
Differences in quality of trace element products: zinc sulfate
The raw material of zinc sulfate is secondary zinc oxide (extracted from flue ash, lead-zinc ore, copper-cadmium slag, etc.). There are two types of products: products with and without iron removal processes, both of which can be used in the production of premix feed. The product has national standards, which has clearly indicated the requirements for main content and hygiene indicators.
Sustar products (in addition to meeting the national standards):
Strictly control chloride ions to slow down the discoloration of premix feed. When using zinc sulfate as premix feed, the chloride ion content should be within 0.5% in summer and within 1% in winter.
The chloride ion content in zinc sulfate can be as high as 3%. High-chloride products tend to absorb moisture and form lumps, and premixes tend to change color.
The product is red in color and contains a large amount of cobalt and manganese, which seriously affects the feed formula.
The product is gray in color and contains calcium and magnesium, which affects the determination of the titration endpoint.
The product contains sulfur, which manifests itself as normal product color, but the packaging turns yellow after the sulfur evaporates.
The production process is poorly managed and the product contains obvious black impurities.
Residual peroxide in zinc sulfate causes the premix product to heat up quickly after the premix is mixed and the premix feed is easy to change color (impurities such as zinc oxide, sulfur trioxide, iron oxide and manganese dioxide).
The color of the titration endpoint of the main content detection is delayed and returns to red quickly.
Differences in quality of trace element products: zinc oxide
Zinc oxide: high-purity zinc oxide (99 zinc oxide) and ordinary zinc oxide (95 zinc oxide), 95 zinc oxide has a large market share.
Production process: There are many production processes for zinc oxide. Different production processes, different raw materials, different calcination temperatures, etc. will cause color change of products.
Indirect method
99 zinc oxide It is produced by calcining zinc ingots Light zinc oxide Bulk density 200-500g/L White.
Direct method
It is produced by calcining zinc suboxide at high temperature Heavy zinc oxide Bulk density 1200-2000g/L Dark yellow Heavy metals seriously exceeded the standard
Acid method
It is produced by chemical synthesis of zinc suboxide via acid method Medium zinc oxide Bulk density 700-1000g/L Slightly yellow to yellow
Ammonia method
It is produced by chemical synthesis of zinc suboxide via ammonia method Medium zinc oxide Bulk density 700-1000g/L White to slightly yellow
Post time: Dec-24-2025
