JPS63117983A - Manufacture of slaked lime for boron-containing fertilizer - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a method for producing slaked lime for fertilizer, and more particularly, is characterized by a method for incorporating boron.

(Prior Art) Boron is an essential fertilizer component for plants, albeit in a small amount, and is mixed with lime. However, boron is difficult to handle, as incorrect dosage can cause chemical damage.

Conventionally, the method for producing boron-containing lime for fertilizer is to crush ore containing 8203, which is native to Turkey, called colemanite, and mix it into a powder of lime such as tankar, slaked lime, or quicklime. This is done by a simple method.

Therefore, in this method, since colemanite itself is a natural stone and is not stable in quality, the boron content tends to vary, and it is extremely difficult to uniformly disperse the powdered colemanite in lime. Furthermore, it is difficult to maintain a constant dosage of boron, which causes important problems in product quality, such as the risk of chemical damage.

(Problems to be Solved by the Invention) Therefore, the present invention focuses on the use of a boric acid solution that is economically a little expensive but has high quality, and also solves the self-drying reaction mechanism that involves the heat generation of quicklime. A manufacturing method has been developed in which powderization and drying can be performed self-contained using the heat of reaction.

[Structure of the Invention] Hereinafter, the present invention will be described in detail. First, limestone is heated in a rotary kiln or the like to obtain quicklime, which is reacted with water, and the following digestion reaction is carried out in a hydrator (digester). prompt.

CaO+H20-→Ca (OH)2 +277kca
l/kg (20°C standard) In this reaction, boric acid (H3BO3) is dissolved in an aqueous solution, and about 0.2 to 1. Stir thoroughly to mix at a ratio of about Owt%.

At the same time, about twice the theoretical amount of excess water is added to compensate for the released water vapor during this reaction.

Then, the digestion reaction is allowed to proceed, and calcium hydroxide is produced by a hydration reaction of calcium oxide, and at the same time, boric acid is uniformly dispersed in the aqueous solution and attached around the calcium hydroxide.

In this reaction, it is desirable to add a formaldehyde solution of melamine resin as digestion water to adjust the hydration reaction. That is, when about 0.3 to 0.8 wt% of a formaldehyde solution of this melamine resin is added to an aqueous boric acid solution, the melamine resin has a water adsorption mechanism on its surface, so it exhibits strong water retention and the reaction H20 on its surface. to be adsorbed. Then, when CaO attacks the adsorbed water,
Digestion reactions proceed step by step, and if left as they were, the reaction might proceed explosively, but the reaction is adjusted to be orderly.

As this reaction progresses, the calcium hydroxide produced undergoes an expansion reaction that causes an increase in volume with respect to calcium oxide, so the calcium hydroxide produced after the reaction collapses due to volume expansion, and automatically Powder.

Further, as the production reaction progresses, heat is generated by an exothermic reaction, and while the remaining water used in the calcium hydroxide is evaporated, the calcium hydroxide itself is self-dried by this heat.

Under this reaction, boric acid H3BO3 is produced by slaked lime C
, a(OH)2 and are uniformly dispersed.

The thus obtained slaked lime is stored in a ripening chamber for a day and night to complete the hydration reaction, thereby obtaining boron-containing slaked lime for fertilizer as a product.

[Effects of the Invention] Based on the above structure, the present invention adds boric acid H3BO3 of stable quality as an aqueous solution during the slaked lime production reaction, so that a certain amount of boron can be accurately mixed into the slaked lime, and the fertilizer It is possible to reliably calculate and mix the amount of boron required as fertilizer, and avoid the negative effects of excessive boron fertilization. Moreover, since it is added to the reaction in the form of an aqueous solution, the dispersion can be made uniform and there is no concentration bias.

In addition, about twice the amount of water theoretically required for the hydration reaction and about 0
．． Since the reaction is allowed to proceed by adding 2 to 1.0 wt% of an aqueous solution of boric acid, the slaked lime produced is self-dried in just the right amount by the heat of the reaction, which is economical.

At the same time, self-powderization due to the expansion reaction proceeds, and when a melamine resin solution is added at this time, the reaction becomes a sequential reaction, promoting the drying and powderization in an orderly manner, suppressing the potentially explosive reaction, and producing The particle size of the product can be made small and uniform.

(Example) Prepare 500 kg of first digestion water for 1000 kg of quicklime, dissolve 5.6 kg of boric acid in this first digestion water, and further dissolve 7.6 kg of formaldehyde solution of melamine resin.
Add kg. Then, proceed with the hydration reaction in the hydrator, and when the reaction progresses to a medium level, add 200 kg of second digestion water.
Add g.

Then, the digestion reaction progresses and slaked lime production begins, but at the same time, the reaction heat raises the temperature to about 550℃, and the temperature rises to about 300℃.
water evaporates and becomes self-drying. In this process, by adding the formaldehyde solution of melamine resin, the swelling reaction proceeds sequentially and the slaked lime is automatically powdered, while the water
01 is retained in the slaked lime, and can prevent scattering of powder peculiar to slaked lime.

This is then stored in a ripening room day and night to obtain a product, with a yield equivalent to approximately 14,000 kg and a particle size of 3.0 mm/
mm or less.

Patent Applicant Tagen Lime Industry Co., Ltd. Agent Patent Attorney Fuku 1) Nao's procedure amendment writing method) 1. Indication of the case Patent Application No. 262964 filed in 1985 2. Name of the invention Method for manufacturing slaked lime for fertilizer containing boron 3.
Relationship with the case of the person making the amendment Patent applicant address: 21-8 Sakaimachi, Tochigi City, Tochigi Prefecture Tagen Sekkai Name: Tagen Lime Industry Co., Ltd. Representative Director Tamura Saju Enso Home Appliances 4, Agent Address: 16-12 Takitanicho, Utsunomiya City, Tochimoto Prefecture No. 5, Date of amendment order Voluntary action 6, Subject of amendment Specification 7, Contents of amendment As attached.

Claims (1)

[Claims] 1) About twice the amount of water theoretically required for the hydration reaction in quicklime and about 0
．． A method for producing slaked lime for fertilizer containing boron, which comprises adding an aqueous solution of 2 to 1.0 wt % of boric acid, and performing drying and powdering in a self-contained manner through a reaction accompanied by heat generation and expansion. 2) The method for producing slaked lime for boron-containing fertilizer according to claim 1, characterized in that a melamine resin solution is added as a regulator of hydration reaction.