Magnesium fertilizers

Uses. A soluble form of magnesium nitrate is used as a fertilizer ia states such as Florida where drainage through the porous, sandy soil depletes the magnesium (see Fertilizers). Magnesium nitrate is also used as a prilling aid in the manufacture of ammonium nitrate. A 0.25—0.50% addition of magnesium nitrate to the process improves the stabHity of the prills and also improves durabHity and abrasion resistance. 

Sodium ferric EDTA Sodium molybdate anhydrous Sodium molybdate dihydrate micronutrient, agric., fertilizers Magnesium sulfate anhydrous micronutrient, animal feed Cobalt sulfate (ous)... 

There are numerous variations of the wet process, but all involve an initial step in which the ore is solubilized in sulfuric acid, or, in a few special instances, in some other acid. Because of this requirement for sulfuric acid, it is obvious that sulfur is a raw material of considerable importance to the fertilizer industry. The acid—rock reaction results in formation of phosphoric acid and the precipitation of calcium sulfate. The second principal step in the wet processes is filtration to separate the phosphoric acid from the precipitated calcium sulfate. Wet-process phosphoric acid (WPA) is much less pure than electric furnace acid, but for most fertilizer production the impurities, such as iron, aluminum, and magnesium, are not objectionable and actually contribute to improved physical condition of the finished fertilizer (35). Impurities also furnish some micronutrient fertilizer elements. 

Some of the principal forms in which sulfur is intentionally incorporated in fertilizers are as sulfates of calcium, ammonium, potassium, magnesium, and as elemental sulfur. Ammonium sulfate [7783-20-2] normal superphosphate, and sulfuric acid frequendy are incorporated in ammoniation granulation processes. Ammonium phosphate—sulfate is an excellent sulfur-containing fertilizer, and its production seems likely to grow. Some common grades of this product are 12—48—0—5S, 12—12S, and 8—32—8—6.5S. 

Hard-burned magnesias may be used in a variety of appHcations such as ceramics (qv), animal feed supplements, acid neutralization, wastewater treatment, leather (qv) tanning, magnesium phosphate cements, magnesium compound manufacturing, fertilizer, or as a raw material for fused magnesia. A patented process has introduced this material as a cation adsorbent for metals removal in wastewater treatment (132). 

Four minerals are the principal commercial sources of potash (Table 2). In all ores, sodium chloride is the principal soluble contaminant. Extraneous water-iasoluble material, eg, clay and siUca, is a significant contaminant ia some of the evaporates being mined from underground deposits. Some European potassium ores contain relatively large amounts of the mineral kieserite, MgS04-H2 0. It is recovered for captive use to produce potassium sulfate compounds or is marketed ia relatively pure form as a water-soluble magnesium fertilizer. 

The value of langbeinite as a fertilizer is enhanced because, in pure form, it contains 18.8 wt % potassium, 11.7 wt % magnesium, and 23.0 wt % sulfur. AH three elements are essential nutrients for plant growth. Commercial grades contain ca 97 wt % mineral the remaining 3 wt % consists of water-insoluble clays and residual sodium chloride. 

Magnesium is removed from brines of the Great Salt Lake in the form of magnesium chloride. This is then used to make elemental magnesium, dust suppressants, and bischofite flake. Magnesium chloride is also used in drilling mud, ion-exchange resins, oxi-chloral cements, fertilizers, and miscellaneous industrial uses. 

Agricultural Use. Citric acid and its ammonium salts are used to form soluble chelates of iron, copper, magnesium, manganese, and zinc micronutrients in Hquid fertilizers (97—103). Citric acid and citrate salts are used in animal feeds to form soluble, easily digestible chelates of essential metal nutrients, enhance feed flavor to increase food uptake, control gastric pH and improve feed efficiency. 

An expanded mica (hydrated magnesium-aluminium-iron silicate). Used in lightweight aggregates, insulation, fertilizer and soil conditioners, as a filler in rubber and paints, and as a catalyst carrier. 

EEC Directive amending Directive 76/116/EEC m respect of the calcium, magnesium, sodium and sulphur content of fertilizers... 

However, the fertilizing effect of nitrates (and sulfates) may be counterbalanced by the leaching of potassium, magnesium, calcium, and other nutrients from forest soils. There is little evidence that agricultural crops are being injured by exposures to nitrates in precipitation. The amount of nitrates in rainwater is almost always... 

Schall192) recommended that the atomic absorption determination of magnesium, calcium, manganese, iron, and copper in fertilizers should be adopted as official, first action. 

Calcium magnesium acetate, 1 127 Calcium magnesium carbonate, health and safety factors related to, 15 74 Calcium monosulfoaluminate, 5 477t Calcium montmorillonite, 6 686, 696 structure and composition, 6 668-669 Calcium nitrate, in nitrogen fertilizers,... 

The pot experiment showed the same differences. The rye grass was cut four times. The greatest differences in the increase in dry matter yield were obtained with the second crop. As all pots received the same basic phosphorus, potassium and magnesium fertilizer, the differences in yield were due to the amount of available nitrogen contained... 

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