CS213813B1 - Method of preparing liquid molybdenum containing concentrates - Google Patents

Description

The invention relates to a process for the preparation of liquid molybdenum-containing concentrators suitable for plant nutrition.

Molybdenum is one of the nutrients that plants need for their healthy development and general life.

The basic physiological function of molybdenum is that it participates in biochemical reactions in the binding of molecular nitrogen and also in the reduction of nitrates. It has been found that the activity of the underlying microorganisms that are capable of binding molecular nitrogen (e.g., Azototactér, Clostridium, etc.) as well as of the nodular bacteria living in symbiosis with butterfly plants (bob, beans, peas, lids, etc.) is closely related. with the presence of plant-accessible forms of molybdenum in the pod.

Plant cells cannot reduce nitrate nitrogen in the absence of molybdenum, which is essential for protein synthesis.

Molybdenum also affects the synthesis and movement of carbohydrates, as well as the formation of chlorophyll and 1-ascorbic acid (vitamin C) in plants. It is also believed that molybdenum will stimulate the activity of the microorganisms in the pod. It is irreplaceable in the inactivation of plant phosphatases.

In the case of molybdenum deficiency, the leaves of the plants have a pale green color, as a result of the reduced nitrogen uptake by the plant. In the case of large molybdenum deficiency chlorotic mesh

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213 813 dies and the leaves curl. Especially susceptible to molybdenum are butterflies (leguminoses) plants (fodder beans, lupines, peas, beans, vetches, etc.). Beetroot, kale, lettuce, tusk, spinach, Satelina, lantern, cauliflower and other vegetables, as well as ropes, hops, citrus plants, cotton and others are sensitive to molybdenum.

Recently, foliar application of aqueous salt solutions containing molybdenum (especially ammonium molybdate) has been able to significantly reduce flower and bud fall in some grape varieties (Neuburgská), which is usually caused by an overdose of nitrogen fertilizers (motivated to obtain the greatest possible benefit).

To eliminate molybdenum deficiency, it is usually recommended to use ammonium or sodium molybdate at a dose of about 2 to 4 kg of ammonium molybdate per hectare (every 3 to 4 years). In foliar applications, 0.01 to 0.05% aqueous ammonium molybdate solutions in an amount of 500 to 700 liters of solution per hectare are most commonly used, and 0.05 to 0.10% solutions of this salt in an amount of 8 to 10 liters of this salt are used for seed pre-treatment aqueous solution per 1 q of seed.

Although the use of molybdates in the form of pure and technical chemicals for plant nutrition and treatment is advantageous from an agrochemical point of view, these substances are relatively expensive and often unavailable in the required amounts.

A number of molybdenum-containing wastes are produced in some industries, but are usually not suitable for fertilizing agricultural plants without further chemical processing. The source of such waste is mainly the metallurgical and metalworking industries, as well as the chemical and electrical industries.

However, the requirements for the properties of concentrates containing trace elements are increased mainly if these are to be applied together with liquid, in particular with clear fertilizers, and if the application is extracorporeal (foliar).

In the electrotechnical industry, the production of incandescent tungsten spirals eliminates strongly acidic solutions with a relatively high molybdenum content (up to about 60 g Mo per liter), which arise from the chemical removal of so-called molybdenum. The malybdenum core of these spirals, after their mechanical-thermal treatment, is dissolved in a mixture of mineral acids containing nitric acid. These acidulosic molluscs are not used in most cases of Salia and constitute an unpleasant and difficult to dispose of liquid waste.

It has now been found that molybdenum-containing liquid concentrates suitable for nourishment and treatment of agricultural plants can be prepared by reacting molybdenum-containing acidic solutions or suspensions with oxide and / or hydroxide and / or magnesium carbonate.

The principle of the invention is that 100 parts by weight of an molybdenum-containing acid solution or sus- pension will undergo a chemical reaction with 5 to 60 parts by weight of dry matter of oxide and / or magnesium hydroxide and / or magnesium carbonate. The urea and optionally other biologically active substances are added to the reaction mixture before, at any time during or after the chemical reaction.

It has been found that it is particularly advantageous to use so-called " macco-burned magnesium oxide prepared by the low-temperature calcination of magnesite or freshly precipitated magnesium hydroxide.

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Optimally, the ratios between the molybdenum-containing acidic solutions or suspensions and the magnesium-containing basic reagents can be determined on the basis of their acidity or resp. alkalinity.

It has also been found that the addition of urea to the liquid reaction product can significantly improve the physicochemical properties of the final formulation (e.g., crystallization temperature, solubility, etc.). During the process, it is preferred to add all or at least some of the urea to the reaction mixture before or during the addition of the magnesium-containing base.

If, for example, a mixture of nitric acid and sulfuric acid was used to dissolve the molybdenum metal, it has proven particularly advantageous to add to the reaction mixture after its chemical reaction with a magnesium-containing base such that urea is present in the final product. ⁺ corresponding to 2 to 2.5, preferably a weight ratio close to 2.3.

An advantage of the process according to the invention is that the obtained liquid concentrate containing molybdenum, magnesium, nitrogen and sulfur is miscible in any proportions with all of the previously used pure, non-pressurized nitrogenous liquid fertilizers, the proposed process being simple and at least -technological equipment.

A great advantage of the process is that it enables the efficient use of acidic molybdenum liquors which fall off in the electrical industry in the production of incandescent and spiral lamps and are difficult to dispose of.

The preparation of liquid concentrates containing molybdenum is illustrated in more detail, but is not limited by the following example.

Example:

To a glass kettle equipped with a stirrer and a reflux condenser was added 83.8 parts by weight of water and 100 parts by volume of acid waste liquor containing mblybdenum were added successively with stirring:

total acidity total N content total Mo content total Fe content total sulfur content

10.46 cm @ -1 of a NaOH solution / 1 g of caustic soda 4.35 wt. %

4.10 wt. %

6.2.10 3 1.%

10.68 wt. % specific gravity at 20 ° C = 1485.1 kg.m \

202.7 parts by weight of technical granular urea (46.2% by weight) were gradually added to the diluted liquor with stirring. % M.

After dissolution of the added amount of urea, 24.5 parts by weight of technical magnesium oxide obtained by thermal treatment of magnesite were successively added with continued stirring.

Magnesium oxide had this composition!

moisture content (at 105 ° C): 0.05 wt. % £ 13 813 Mg content Ca content Fe content Al approx. Al approx. Total alkalinity: 55,40 wt. %: 1.50 wt. %: 3.80 wt. % i 0.50 wt. %: 223.9 cm < ^{3 &gt}; of 2N HgSO4 / lg powder of technical magnesium oxide.

The reaction mixture was maintained at 80 ° C for 1 hour with vigorous stirring.

After the reaction time, the reaction mixture thus prepared was allowed to settle and after separation and separation of the sludge, 400 parts by weight of a blue-colored acid solution corresponding to a pH of 6.5 were obtained.

The final product had the following composition:

23.8 wt. % of total N

1.0 wt. % Mo

3.3 wt. % Mg (5.5 wt.% MgO).

Claims (1)

Process for preparing molybdenum-containing liquid concentrates suitable for nutrition and treatment of agricultural plants by reacting molybdenum-containing acidic solutions or suspensions with oxide and / or magnesium carbonate and / or characterized in that 100 parts by weight of molybdenum-containing acidic solution or suspension and undergoing chemical reaction From 5 to 60 parts by weight of dry matter of oxide and / or magnesium hydroxide and / or magnesium carbonate and before, during or after the chemical reaction, urea and other biologically active substances are added to the reaction mixture.