CN1506335A

CN1506335A - Synthesis of urea-formaldehyde controlled releasing fertilizer

Info

Publication number: CN1506335A
Application number: CNA021555680A
Authority: CN
Inventors: 邢礼军; 李亚星; 徐秋明; 王幼珊; 倪小会
Original assignee: Institute Of Plant Nutrition And Resources Beijing Academy Of Agricultural And Forestry Sciences
Current assignee: Institute Of Plant Nutrition And Resources Beijing Academy Of Agricultural And Forestry Sciences
Priority date: 2002-12-11
Filing date: 2002-12-11
Publication date: 2004-06-23
Anticipated expiration: 2022-12-11
Also published as: CN1218907C

Abstract

The synthesis process of urea-formaldehyde controlled releasing fertilizer includes mixing gelatinized starch and urea, adding the mixture of polymer water absorbing resin and formaldehyde solution, adding vegetable oil, organic matter including turf and stalk and adsorbent including zeolite, adding sulfuric acid for acidifying to obtain solid product, and final drying, crushing and sieving to obtain the product. The said process avoids excessive crosslinking of polymer to raise the utility of nitrogen, avoids volatizing of formaldehyde during reaction to raise environment quality and production efficiency, and adds zeolite and other inorganic stuffing to raise product quality and provide water maintaining and fertilizer maintaining function and trace elements. In addition, phosphate fertilizer and potash fertilizer may be also added to produce re-compounded fertilizer.

Description

A kind of synthetic method of urea aldehyde release and release control fertilizer

Technical field

The present invention relates to the manufacture method of chemical fertilizer, the synthetic method of a kind of urea aldehyde release and release control fertilizer of more specifically saying so.

Background technology

Urea formaldehyde claims urea-formaldehyde fertilizer again, and nineteen fifty-five begins to be produced by BASF AG, is the slow release fertilizer that first commercialization is produced.Urea formaldehyde is to be formed by urea and formaldehyde condensation, is white, tasteless powder or particulate state.Different according to the mol ratio (U/F) of urea and formaldehyde can make the different urea-formaldehyde fertilizer of condensation degree.The preparation process of common urea-formaldehyde fertilizer: urea and formaldehyde join in the reactor by a certain percentage, make the urea surplus, to prevent excessive polymerization, the mol ratio of controlling urea and formaldehyde usually was greater than 1: 1, and be alkalescence with the NaOH regulator solution, reaction at a certain temperature; Subsequently, add sulfuric acid, make solution be acid, promote condensation reaction; Reactant makes urea-formaldehyde fertilizer through curing, drying, pulverizing and screening.In this type of synthetic method, contain the rapid acidifying of the aqueous solution of urea and formaldehyde, obtain solid-state condensation product, be under the condition of strictness, formaldehyde solution to be added in the urea aqueous solution lentamente to prevent that formaldehyde from overflowing as the DE2422238 patent; Then be that urea contacts with formaldehyde solution in the US4173582 patent, with the solution acidifying that generates, obtain the solid condensation product then, obtain filter cake after filtration, filtrate is returned in the urea dissolution vessel recycled subsequently.

The subject matter that above-mentioned prior art exists:

Formaldehyde easily overflows in the polymerization process; Unreacted urea does not have slow release effect in the polymerization process: polymerization reactant was all once poor during strong solution was synthetic, and sudden and violent poly-reaction (the too high crosslinking reaction that causes polycondensate of partial concn, the validity of impact polymer) easily takes place; The slowly-releasing cycle of urea formaldehyde controlled-release fertilizer is long, the validity of impact polymer nitrogen, and granular and powdered slowly-releasing process is distinguished little.

Summary of the invention

The objective of the invention is to overcome the shortcoming of prior art, propose a kind of synthetic method of improved urea-formaldehyde fertilizer.

The synthetic method of urea aldehyde release and release control fertilizer of the present invention comprises following process:

(1) starch is added to the water, is heated to boiling, insulation 10-15min, make it gelatinization, it is saturated to solution to add urea then, reheat to 40 ℃, obtain solution I, described starch content is the 5-10% of the weight of water, and described starch comprises wheat-flour, Semen Maydis powder, sweet potato powder;

(2) with concentration 37% formaldehyde and water-absorbing resin with weight ratio 100-150: 1 mixes, the solution I mixing that the solution that obtains obtains with step (1) again obtains urea and formaldehyde mole ratio is the solution II of 1.2-2.5, and described water-absorbing resin comprises polyacrylamide resin, starch graft acrylic acid resin;

(3) be 8.0-10.0 with the PH of the NaOH regulator solution II of 10% concentration rapidly, add non-edible plant oil covering surfaces 3-8mm then, stir, be warming up to 40-60 ℃, insulation 30-60min obtains solution III, and described vegetables oil comprises turps, Oleum Gossypii semen;

(4) get 1/2 of solution III that step (3) obtains and put into another reactor, then with the organism that comprises the peat composed of rotten mosses, straw, sawdust of drying, pulverizing with comprise the sorbent material of zeolite powder, attapulgite, directly join among the reaction soln III, its add-on is the 10-20% of urea, stir, at the uniform velocity add the H of 20% concentration then ₂SO ₄, the limit edged stirs, and stops to add H now immediately when being settled out ₂SO ₄, add 1/2 other solution III again, stir, obtain slurry, adding H ₂SO ₄To take cooling measure with anti-riot poly-in the process;

(5) slurry that step (4) is obtained dehydrates, pulverizes, crosses the 2mm sieve and promptly makes required urea-formaldehyde fertilizer under 80-100 ℃.

In the slurry of described step (4) routinely ratio add phosphate fertilizer, potash fertilizer at interior fertilizer, dehydrate, pulverize, cross the 2mm sieve then, make composite fertilizer.

Described urea meets national standard, and formaldehyde meets the GB technical grade.

Described starch comprises the non-putrid cheap various starch of the dust collection thing of Semen Maydis powder, sweet potato powder, wheat and milling plant.

Described water-absorbing resin, its suction multiple is 100-150 times.

Described sorbent material comprises zeolite powder, attapulgite clay powder, and its granularity is 200 orders.

The described peat composed of rotten mosses, straw, sawmilling organism water content are lower than 5%, and are crushed to 2mm.

The advantage and the effect of invention:

1. by dosing mineral filler (attapulgite, zeolite etc.) and organism (starch and straw powder etc.), avoided the excessive crosslinking reaction of polymkeric substance effectively, the validity of nitrogen in the polymkeric substance is improved.

2. cover non-edible plant oil as turps, cottonseed wet goods by solution surface, efficiently solve the volatilization of formaldehyde in reaction process, improved environmental quality and production efficiency.

3. by dosing mineral filler such as zeolite etc., the quality of product is improved, and has water conservation, protects fertile and the function of effective micro-mineral element is provided.

The present invention prepare in the urea formaldehyde fertilizer process quantitatively add industrial starch and vegetables oil after, reach the purpose of controlled release by the composition that changes its C/N ratio, and the validity of nitrogen improved; Absorption property inorganic, organic additive also can make unreacted urea have slow-release function; Realized the jump of slow release fertilizer by the inorganic and organic additive that adds, can realize producing the different fertilizer variety of cost performance, satisfied the requirement of Different Crop according to Different Crop growth characteristics and regulation of fertilizer requirement to the matter of release and release control fertilizer.

5. synthetic urea aldehyde product of the present invention can be used separately, also can be in preparation process adds phosphate fertilizer and potash fertilizer in desired ratio, directly granulation, sieves, and produces slow-release compound fertilizer.

Above-mentioned these characteristics are not have about the technology of synthetic urea formaldehyde as slow release fertilizer in the past.

Embodiment

Example 1

The urea aldehyde release and release control fertilizer preparation process of this example is as follows:

1. weighing 20.0g flour joins in the 1000ml beaker, adds water 240.0g, is heated to boiling, insulation 5min;

2. after stopping heating, 272.0g urea is directly joined in the solution of step (1);

3. beaker is placed 60 ℃ water bath with thermostatic control, when urea all adds (the prior 1.7g of adding polyacrylamide water-absorbing resin uses behind the imbibition fully in the 170ml formaldehyde solution) in the solution with 170ml formaldehyde solution (37%) average rate after the dissolving;

4. mensuration pH value, and, add the 50ml Oleum Gossypii semen then with 10%NaOH regulator solution PH to 8.0, make it be covered in solution surface, be statically placed in the water-bath after stirring gently, after solution is warming up to 60 ℃, begin to clock insulation 40min;

5. weighing 60g zeolite powder (200 order) places another 1000ml beaker, and half of the reaction soln of step (4) is transferred in the beaker of containing zeolite powder, with 4ml20%H ₂SO ₄Solution at the uniform velocity joins in the reaction soln, and the limit edged stirs, and when being settled out current second half reaction soln that adds, is stirred to till the form slurry;

6. reactant is placed 80 ℃ of dryings of loft drier, pulverize then, cross the 2mm sieve, promptly obtain required product.

Product performance: nitrogenous 31%, activity quotient A is I0.42, and the U/F mol ratio is 2.0.

Example 2

This example is for testing with the potted plant rape of fertilizer of the present invention.

The plastic tub of cut-off footpath 16.5 * high 15.5cm is adorned native 1.2kg, single fertilization, and rate of fertilizer application is: phosphorus P ₂O ₅Be 0.1g/kg soil, potassium K ₂O is a 0.15g/kg soil, and the fertile nitrogen of urea (U) and urea formaldehyde of the present invention (UF) is by four processing horizontals 0 (CK), and 0.2 (U1, UF1), 0.4 (U2, UF2), 0.6 (U3, UF3) g/kg soil applies.4 repetitions are established in 3 of every basin field planting.Results after one month.

Experimental result sees Table 1-5.

Potted plant rape experiment by table 1-5 shows: compare with common urea, when adopting 6 times of normal amount of nitrogen to make base fertilizer, synthetic fertilizer of the present invention can normal growth, and urea then burns seedling and all dead; When making base fertilizer for 2,4 times that adopt normal amount of nitrogen, fertilizer overground part fresh weight of the present invention is respectively 2.2,3.3 times that equal nitrogen content urea is supported, and it is respectively 2.8,3.5 times of equal nitrogen content urea that the overground part dry weight is used fertilizer of the present invention; Whole plant nitrogen absorbing amount, 2.5,2.6 times of using fertilizer of the present invention and be respectively equal nitrogen content urea.Prove that thus fertilizer of the present invention has improved fertilizer utilization ratio really on the basis of slowly-releasing.

Table 1 plant fresh weight (unit: the g/ basin)

Project	The overground part fresh weight					The underground part fresh weight
	The overground part fresh weight					The underground part fresh weight					????1	????2	????3	???4	On average	??1	????2	???3	???4	On average
	??CK	??11.9	??7.74	??15.17	??9.25	??11.01	??3.61	??2.05	??1.5	??1.63	????1	????2	????3	???4	On average	??1	????2	???3	???4	On average	??2.197
??U1	??CK	??11.9	??7.74	??15.17	??9.25	??11.01	??3.61	??2.05	??1.5	??1.63	??8.53	??8.19	??9.28	??6.8	??8.2	??0.28	??0.27	??0.32	??0.27	??0.285	??2.197
??U1	??U2	??5.4	??6.54	??4.73	??3.73	??5.1	??0.12	??0.17	??0.17	??0.09	??8.53	??8.19	??9.28	??6.8	??8.2	??0.28	??0.27	??0.32	??0.27	??0.285	??0.137
??UF1	??U2	??5.4	??6.54	??4.73	??3.73	??5.1	??0.12	??0.17	??0.17	??0.09	??15.24	??17.17	??19.49	??22.89	??18.69	??0.84	??0.9	??1.07	??1.4	??1.052	??0.137
??UF1	??UF2	??15.45	??21.7	??20.85	??10.18	??17.04	??0.49	??1.12	??0.77	??0.21	??15.24	??17.17	??19.49	??22.89	??18.69	??0.84	??0.9	??1.07	??1.4	??1.052	??0.647
??UF3	??UF2	??15.45	??21.7	??20.85	??10.18	??17.04	??0.49	??1.12	??0.77	??0.21	??2.64	??8.73	??4.63	??10.76	??6.69	??0.2	??0.23	??0.18	??0.29	??0.225	??0.647

Table 2 plant dry weight (unit: the g/ basin)

Project	The ground dry weight					Underground dry weight
	The ground dry weight					Underground dry weight					????1	????2	????3	????4	On average	????1	???2	???3	???4	On average
	??CK	??1	??0.78	??1.27	??0.92	??0.992	??0.42	??0.46	??0.33	??0.38	????1	????2	????3	????4	On average	????1	???2	???3	???4	On average	??0.397
??U1	??CK	??1	??0.78	??1.27	??0.92	??0.992	??0.42	??0.46	??0.33	??0.38	??0.53	??0.51	??0.56	??0.5	??0.525	??0.05	??0.06	??0.1	??0.08	??0.072	??0.397
??U1	??U2	??0.35	??0.42	??0.35	??0.24	??0.34	??0.03	??0.05	??0.03	??0.02	??0.53	??0.51	??0.56	??0.5	??0.525	??0.05	??0.06	??0.1	??0.08	??0.072	??0.032
??UF1	??U2	??0.35	??0.42	??0.35	??0.24	??0.34	??0.03	??0.05	??0.03	??0.02	??1.14	??1.29	??1.55	??1.68	??1.415	??0.15	??0.19	??0.21	??0.4	??0.237	??0.032
??UF1	??UF2	??1.02	??1.66	??1.44	??0.71	??1.207	??0.13	??0.28	??0.16	??0.04	??1.14	??1.29	??1.55	??1.68	??1.415	??0.15	??0.19	??0.21	??0.4	??0.237	??0.152
??UF3	??UF2	??1.02	??1.66	??1.44	??0.71	??1.207	??0.13	??0.28	??0.16	??0.04	??0.22	??0.69	??0.38	??0.84	??0.532	??0.12	??0.05	??0.03	??0.08	??0.07	??0.152

Table 3 Soil Nitrogen residual content (unit: the g/ basin)

Project	????????????????????????NH ₄-N				?????????????????????NO ₃-N
	????????????????????????NH ₄-N				?????????????????????NO ₃-N				????1	????2	????3	On average	????1	????2	????3	On average
	??CK	??5.83	??4.5	????7	???5.78	????3.75	??2.98	??2.83	????1	????2	????3	On average	????1	????2	????3	On average	????3.19
??U1	??CK	??5.83	??4.5	????7	???5.78	????3.75	??2.98	??2.83	??8.33	??8.41	????6.51	???7.75	????20.9	??7.04	??29.8	????19.25	????3.19
??U1	??U2	??9.05	??9.61	????8.23	???8.96	????60.1	??21.6	??77.6	??8.33	??8.41	????6.51	???7.75	????20.9	??7.04	??29.8	????19.25	????53.1
??U3	??U2	??9.05	??9.61	????8.23	???8.96	????60.1	??21.6	??77.6	??9.78	??8.66	????11	???9.81	????151	??142	??96.8	????129.93	????53.1
??U3	??UF1	??3.67	??3.04	????6.75	???4.49	????9.79	??14.8	??11.2	??9.78	??8.66	????11	???9.81	????151	??142	??96.8	????129.93	????11.93
??UF2	??UF1	??3.67	??3.04	????6.75	???4.49	????9.79	??14.8	??11.2	??4.58	??9.25	????4.92	???6.25	????35.3	??73.2	??26.2	????44.9	????11.93
??UF2	??UF3	??6.5	??9.42	????7.7	???7.87	????128	??106	??75.4	??4.58	??9.25	????4.92	???6.25	????35.3	??73.2	??26.2	????44.9	????103.13

Table 4 plant N contains heavily (unit: %)

Project	Overground part N content					Underground part N content
	Overground part N content					Underground part N content	????1	?????2	???3	???4	On average	??????1
	??CK	??2.69	???2.64	?3.46	??2.7	???2.8725	????1	?????2	???3	???4	On average	??????1	????1.09
??U1	??CK	??2.69	???2.64	?3.46	??2.7	???2.8725	??4.5	???4.36	?4.88	??4.46	???4.55	????1.62	????1.09
??U1	??U2	??5.26	???5.29	?5.21	??5.01	???5.1925	??4.5	???4.36	?4.88	??4.46	???4.55	????1.62	????1.69
??UF1	??U2	??5.26	???5.29	?5.21	??5.01	???5.1925	??4.06	???4.48	?4.18	??3.91	???4.1575	????1.62	????1.69
??UF1	??UF2	??4.91	???4.41	?5.02	??4.97	???4.8275	??4.06	???4.48	?4.18	??3.91	???4.1575	????1.62	????1.62
??UF3	??UF2	??4.91	???4.41	?5.02	??4.97	???4.8275	??5.03	???5.18	?5	??5.16	???5.0925	????1.3	????1.62

The total amount of nitrogen sucking of table 5 strain

Project	Overground part dry weight (g/ basin)	Overground part nitrogen content (%)	The total absorption of N of overground part (g/ box)	Underground part dry weight (g/ basin)	Underground part nitrogen content (%)	The total absorption of N of underground part (g/ basin)	Plant always inhales nitrogen N (g/ basin)
Project	Overground part dry weight (g/ basin)	Overground part nitrogen content (%)	The total absorption of N of overground part (g/ box)	Underground part dry weight (g/ basin)	Underground part nitrogen content (%)	The total absorption of N of underground part (g/ basin)	Plant always inhales nitrogen N (g/ basin)	CK	?0.99	2.87	?2.87	?0.4	?1.09	?0.44	?3.31
U1	?0.53	4.55	?2.41	?0.07	?1.62	?0.11	?2.52	CK	?0.99	2.87	?2.87	?0.4	?1.09	?0.44	?3.31
U1	?0.53	4.55	?2.41	?0.07	?1.62	?0.11	?2.52	U2	?0.34	5.19	?1.76	?0.33	?1.69	?0.56	?2.32
UF1	?1.42	4.16	?5.91	?0.24	?1.62	?0.39	?6.3	U2	?0.34	5.19	?1.76	?0.33	?1.69	?0.56	?2.32
UF1	?1.42	4.16	?5.91	?0.24	?1.62	?0.39	?6.3	UF2	?1.21	4.83	?5.84	?0.15	?1.62	?0.24	?6.08
UF3	?0.53	5.09	?2.7	?0.07	?1.34	?0.09	?2.79	UF2	?1.21	4.83	?5.84	?0.15	?1.62	?0.24	?6.08

Claims

1. the synthetic method of a urea aldehyde release and release control fertilizer is characterized in that preparation process may further comprise the steps:

(4) get 1/2 of solution III that step (3) obtains and put into another reactor, then with the organism that comprises the peat composed of rotten mosses, straw, sawdust of drying, pulverizing with comprise the sorbent material of zeolite, Attapulgite, directly join among the reaction soln III, its add-on is the 10-20% of urea, stir, at the uniform velocity add the H of 20% concentration then ₂SO ₄, the limit edged stirs, and stops to add H now immediately when being settled out ₂SO ₄, add 1/2 other solution III again, stir, obtain slurry, adding H ₂SO ₄To take cooling measure with anti-riot poly-in the process;

2. according to the described synthetic method of claim 1, it is characterized in that: in the slurry of step (4), add phosphate fertilizer, potash fertilizer, and then, make composite fertilizer with urea aldehyde release and release control fertilizer through dehydrating, pulverize, cross the 2mm sieve.