Urea formaldehyde (UF) sustained-release fertilizers and production process thereof

Abstract

The invention provides sustained and controlled release fertilizers which are urea formaldehyde (UF) sustained-release fertilizers. The fertilizers are chemical type sustained-release fertilizers synthesized from urea and formaldehyde. According to a production process of the fertilizers, through the control over the reaction conditions such as raw material ratio, pH value, temperature and reaction time, sustained-release fertilizers with different effect periods can be produced. That is to say, fast-acting, medium-acting and long-acting sustained-release fertilizers can be produced. Therefore, fertilizer deficiency during a seedling stage is prevented, plant growth is vigorous, fertilizer shortage in a late stage is prevented, and yield improvement can be realized. Through the regulation upon the production process, various products with fertilizer effects of 50-60 days, 90-120 days and more than one year can be produced; and fertilizer utilization rate can be improved by more than 1 time. The fertilizers can be widely applied in agriculture, forestry, urban greening, and engineering greening. The fertilizers can be used independently, can be used with other fertilizers, and can be prepared into various compound fertilizers. The production process is simple and feasible, and has the advantages of low investment, fast effect, sufficient raw materials, and vast market.

Description

technical field

[0001] The invention belongs to urea-formaldehyde slow-release fertilizer in slow-release and controlled-release fertilizers, and in particular relates to a chemical slow-release fertilizer formed by compounding (polymerizing) urea and formaldehyde——urea-formaldehyde (UF) slow-release fertilizer and its production process. Background technique

[0002] The development direction of slow and controlled release fertilizers is a new type of fertilizer in the 21st century. Its advantages are slow decomposition and release in the soil, extended fertilizer effect period, and improved utilization rate. In agriculture, one-time fertilization can be used to avoid the process of top dressing, so that the process of decomposition, release, and fertilizer supply can be absorbed by crops. The law of fertilizer demand is basically coordinated, and the comprehensive benefits of saving fertilizer, labor, and increasing production can be achieved; in the industry and the nation...

Examples

Embodiment 1

[0019] A urea-formaldehyde slow-release fertilizer is composed of the following molar ratios of raw materials: urea: formaldehyde = 1:1, and its production process is as follows:

[0020] Take 100 kg of urea (with a nitrogen content greater than or equal to 46%) and 100 kg of formaldehyde (with a content greater than or equal to 36%) according to the above ratio, add them to the reactor, and proceed under the following reaction conditions: addition reaction pH 8.0, temperature 80 ° C, The time is 30 minutes, the polymerization reaction pH is 4.5, the temperature is 55°C, and the time is 1 hour; then it can be centrifuged, dried and pulverized.

[0021] The main technical indicators of the produced urea-formaldehyde are:

[0022] Total nitrogen content: 38.5%; cold water insoluble nitrogen 25.5%; activity coefficient: 52%; biuret 0.4%; moisture: 2.6%.

Embodiment 2

[0024] A urea-formaldehyde slow-release fertilizer is composed of the following molar ratios of raw materials: urea: formaldehyde = 2:1, and its production process is as follows:

[0025] Take 200 kg of urea (with a nitrogen content greater than or equal to 46%) and 100 kg of formaldehyde (with a content greater than or equal to 36%) according to the above ratio, add them to the reactor, and proceed under the following reaction conditions: addition reaction pH 8.5, temperature 78 ° C, The reaction time is 40 minutes, the polymerization reaction pH is 4.2, the temperature is 50°C, and the time is 55 minutes; then it can be centrifuged, dried and pulverized.

[0026] The main technical indicators of the produced urea-formaldehyde are:

[0027] Total nitrogen content: 39.0%; cold water insoluble nitrogen 26.1%; activity coefficient: 48%; biuret 0.35%; moisture: 2.3%.

Embodiment 3

[0029] A urea-formaldehyde slow-release fertilizer is composed of the following molar ratios of raw materials: urea: formaldehyde = 1.5:1, and its production process is as follows:

[0030] Take 150 kg of urea (with a nitrogen content greater than or equal to 46%) and 100 kg of formaldehyde (with a content greater than or equal to 36%) according to the above ratio, add them to the reactor, and proceed under the following reaction conditions: addition reaction pH 7.8, temperature 65 ° C, The reaction time is 2 hours, the polymerization reaction pH is 5.6, the temperature is 45°C, and the time is 42 minutes; then it can be centrifuged, dried and pulverized.

[0031] The main technical indicators of the produced urea-formaldehyde are:

[0032] Total nitrogen content: 38.8%; cold water insoluble nitrogen 26.8%; activity coefficient: 51%; biuret 0.41%; moisture: 1.9%.

technical field

[0001] The invention belongs to urea-formaldehyde slow-release fertilizer in slow-release and controlled-release fertilizers, and in particular relates to a chemical slow-release fertilizer formed by compounding (polymerizing) urea and formaldehyde——urea-formaldehyde (UF) slow-release fertilizer and its production process. Background technique

[0002] The development direction of slow and controlled release fertilizers is a new type of fertilizer in the 21st century. Its advantages are slow decomposition and release in the soil, extended fertilizer effect period, and improved utilization rate. In agriculture, one-time fertilization can be used to avoid the process of top dressing, so that the process of decomposition, release, and fertilizer supply can be absorbed by crops. The law of fertilizer demand is basically coordinated, and the comprehensive benefits of saving fertilizer, labor, and increasing production can be achieved; in the industry and the nation...

Examples

Embodiment 1

[0019] A urea-formaldehyde slow-release fertilizer is composed of the following molar ratios of raw materials: urea: formaldehyde = 1:1, and its production process is as follows:

[0020] Take 100 kg of urea (with a nitrogen content greater than or equal to 46%) and 100 kg of formaldehyde (with a content greater than or equal to 36%) according to the above ratio, add them to the reactor, and proceed under the following reaction conditions: addition reaction pH 8.0, temperature 80 ° C, The time is 30 minutes, the polymerization reaction pH is 4.5, the temperature is 55°C, and the time is 1 hour; then it can be centrifuged, dried and pulverized.

[0021] The main technical indicators of the produced urea-formaldehyde are:

[0022] Total nitrogen content: 38.5%; cold water insoluble nitrogen 25.5%; activity coefficient: 52%; biuret 0.4%; moisture: 2.6%.

Embodiment 2

[0024] A urea-formaldehyde slow-release fertilizer is composed of the following molar ratios of raw materials: urea: formaldehyde = 2:1, and its production process is as follows:

[0025] Take 200 kg of urea (with a nitrogen content greater than or equal to 46%) and 100 kg of formaldehyde (with a content greater than or equal to 36%) according to the above ratio, add them to the reactor, and proceed under the following reaction conditions: addition reaction pH 8.5, temperature 78 ° C, The reaction time is 40 minutes, the polymerization reaction pH is 4.2, the temperature is 50°C, and the time is 55 minutes; then it can be centrifuged, dried and pulverized.

[0026] The main technical indicators of the produced urea-formaldehyde are:

[0027] Total nitrogen content: 39.0%; cold water insoluble nitrogen 26.1%; activity coefficient: 48%; biuret 0.35%; moisture: 2.3%.

Embodiment 3

[0029] A urea-formaldehyde slow-release fertilizer is composed of the following molar ratios of raw materials: urea: formaldehyde = 1.5:1, and its production process is as follows:

[0030] Take 150 kg of urea (with a nitrogen content greater than or equal to 46%) and 100 kg of formaldehyde (with a content greater than or equal to 36%) according to the above ratio, add them to the reactor, and proceed under the following reaction conditions: addition reaction pH 7.8, temperature 65 ° C, The reaction time is 2 hours, the polymerization reaction pH is 5.6, the temperature is 45°C, and the time is 42 minutes; then it can be centrifuged, dried and pulverized.

[0031] The main technical indicators of the produced urea-formaldehyde are:

[0032] Total nitrogen content: 38.8%; cold water insoluble nitrogen 26.8%; activity coefficient: 51%; biuret 0.41%; moisture: 1.9%.

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