1. Key points for selection of agricultural applications

(1)Functional requirements and purity requirements

Supplement magnesium: Choose agricultural grade magnesium sulfate monohydrate (purity > 95%), magnesium content > 14%, used to correct magnesium deficiency symptoms of crops (such as yellowing of leaves, weakened photosynthesis), especially suitable for magnesium-requiring crops such as tomatoes, potatoes, and roses.

Soil improvement: Prioritize products containing free acid (pH 3-4), which can adjust acidic soil, improve water retention and looseness, and avoid soil compaction.

(2) Adaptation of morphology and application method

Foliar spraying: High solubility (easily soluble in water), recommended concentration of 0.1%-0.3%, quickly supplement magnesium and alleviate yellowing symptoms 36.

Base fertilizer mixed application: Granules are used in combination with organic fertilizers, with a dosage of 5-10 kg per mu, and avoid mixing with alkaline fertilizers (such as wood ash) to prevent magnesium ions from being fixed.

(3) Safety and environmental protection

The content of heavy metals (lead, arsenic) must comply with the "Fertilizer Safety Standard" (GB 38400-2019) to avoid soil pollution; priority should be given to integrated production that has passed green certification to extend the fertilizer effect cycle

2. Key points for industrial application selection

(1) Scenario adaptation and purity standards

Chemical manufacturing: high-purity magnesium sulfate monohydrate (MgSO>98%) is required, and water-insoluble matter ≤0.5%, which is used to produce flame retardants, ceramic glazes, etc. to avoid impurities interfering with chemical reactions.

Sewage treatment: Select industrial-grade products (purity e>95%), which are used to flocculate suspended matter or remove phosphates. pH adjustment (9-11) and stirring processes are required to improve treatment efficiency.

(2) Stability and economy

Advantages of drying type: Magnesium sulfate monohydrate contains less crystal water, and its stability is better than that of heptahydrate, which is suitable for long-term storage and high temperature environment (such as papermaking and printing and dyeing industry)

Utilization of by-products: Magnesium sulfate monohydrate, which is a by-product of titanium dioxide, is low-cost and environmentally friendly, and is suitable for large-scale water treatment or building materials production (such as magnesium sulfate board)

(3) Environmental certification and operating specifications

Choose products that have passed ROHS certification to ensure that there is no heavy metal residue after industrial waste treatment; wear protective equipment during operation to avoid dust inhalation or skin contact

3. General precautions for industry and agriculture

(1) Storage management

Seal and moisture-proof to avoid agglomeration (agriculture) or moisture absorption and agglomeration (industry); industrial drying type can be stored for a long time, and agricultural granules need to be stored away from light.

(2) Safe application

Agriculture avoids excessive use (≤15 kg per mu) to prevent soil acidification or magnesium poisoning: industrial addition requires sufficient stirring to prevent precipitation from affecting equipment operation.

(3) Quality verification

Dissolution test: High-quality magnesium sulfate monohydrate dissolves quickly, the solution is transparent, and there are few residual particles (agricultural applicability verification).

pH detection: After dissolution, the solution is close to neutral (pH 6-7). If the acidity is too strong, it may contain free acid impurities (need to be judged in combination with industrial needs)