CN1006781B

CN1006781B - Slaked lime composition and method for preparing

Info

Publication number: CN1006781B
Application number: CN 85106732
Authority: CN
Inventors: 浦野辉男; 宫路宽
Original assignee: Murakashi Lime Co ltd
Current assignee: Murakashi Lime Co ltd
Priority date: 1984-03-09
Filing date: 1985-09-06
Publication date: 1990-02-14
Also published as: CN85106732A

Abstract

The present invention relates to a slaked lime composition with the improved eluviation performance, and a preparing method thereof. The preparing method comprises the steps as follows: adding polytetrafluoroethylene to slaked lime or the mixture of the slaked lime and a hydrate of calcined dolomite; wrapping the prepared lime granules in a microfilament net formed by the polytetrafluoroethylene.

Description

Slaked lime composition and method for preparing

The present invention has narrated a kind of slaked lime composition, is reduced because of leaching loss that rainwater and analogue caused in the said composition, and prepares this method for compositions.

Use slaked lime composition in soil, particularly white lime fertilizer is in order to regulate the acidity of soil.White lime fertilizer roughly is divided into following three kinds, the lime carbonate fertilizer of producing by crushed limestone, rhombspar or other analogous material; By at about 1000 ℃ of temperature lower calcination unslaked limes, regulate its globule size and the unslaked lime fertilizer produced, the white lime fertilizer that obtains by hydration unslaked lime.

Can select the fertilizer of different structure according to purposes, but the dissolubility difference of these fertilizer in water is very big.For example: lime carbonate (Ca CO ₃) solubleness in water is within 1.4 to 1.5 milligrams/100 gram (20 ℃) scopes, and white lime [Ca(OH) ₂] solubleness in water is 126 milligrams/100 grams (20 ℃).

The difference of solubleness has caused in the soil another difference of neutralization reaction speed between the acidic components and fertilizer.Therefore, even granulometric facies together, the lime carbonate fertilizer that white lime compares can make neutralization reaction finish quickly.

On the other hand, unslaked lime fertilizer and white lime fertilizer granulometric facies like the time, have and be close to identical speed of reaction.Generally speaking, these fertilizer are that diameter is about 1 to 5 millimeter particle or fritter.

Granular unslaked lime by the water hydration, is transformed into white lime in soil, but meanwhile, owing to the required water of hydration is present in the soil in a large number, so the white lime that generates is bulk, rather than Powdered.Moisture white lime makes carbonation reaction and hydration reaction almost generate lime carbonate simultaneously.For this reason, the neutralization reaction speed of unslaked lime fertilizer is lower than the neutralization reaction speed of Powdered white lime fertilizer.In brief, the speed of white lime fertilizer adjusting soil acidity is higher than the lime manure of other structure, and in fact, this only is theoretic meaning.Therefore white lime fertilizer solubility height is easy to by rainwater and other analogue institute leaching, so during plant-growth, can not continue to keep the soil appropriate acidity.

In view of the foregoing, the general practice is that elder generation is adjusted to required acidity with white lime with strongly acidic soil, is sprinkled into the lime manure of another kind of structure then in soil, perhaps white lime fertilizer and another kind of lime manure is sprinkled into soil simultaneously.

The purpose of this invention is to provide a kind of slaked lime composition, particularly this composition can reduce the leaching loss that is caused by rainwater or analogue, has therefore improved retention and don't weakened it direct effect and obvious characteristic when improving soil acidity.The preparation method of this slaked lime composition is as follows: at first tetrafluoroethylene (being called PTFE later on) is added in the white lime powder; This mixture is applied the hot pressing shearing force, so that form the microfilament of PTFE resin; Then to wherein adding the white lime particle, like this, the white lime particle caking that just can loosen.

Fig. 1 illustrates based on the relation between pH value and the experience fate, regulates the test-results of soil acidity with white lime fertilizer of the present invention and untreated white lime fertilizer.

The similar Fig. 1 of Fig. 2, but be based on the amount of lime that is replaced and experience the test-results that concerns between the fate.

The above-mentioned PTFE that the present invention is used is added in the fine powder, and through suitably processing, PTFE has the characteristic that changes over netted microfilament and don't change chemical property, and the fine grained of white lime is constrained in the spider web, forms piece on the surface. The caking that obtains so is not a kind of intensive fine powder, such as particle, and is the fine powder that loosens fully, and wherein the white lime fine grained constrains in the net of microfilament formation. Therefore, compare with the white lime material of not processing with PTFE, the white lime caking of processing through PTFE can keep regulating action and the governing speed to soil acidity of same degree, and can greatly reduce the leaching loss that is caused by rainwater and analog.

When preparing composition of the present invention,, after adding PTFE, be necessary that one or many mixes, compression/shearing and heat treated so if desire forms the character that microfilament keeps the white lime caking by PTFE is added in the white lime.If the consumption of PTFE and treatment condition are suitable, these processing are formed in several seconds or the several minutes protofibril of PTFE and finish, and form spider web, and the fine particle of white lime is lumpd therein.

According to another kind of method, earlier PTFE is dispersed in the water, its water yield will be enough to the mixture of a kind of unslaked lime of hydration or unslaked lime and dolomite type lime, make it be transformed into white lime, use prepared suspension liquid hydration unslaked lime then, and under hydration reaction heat and stirring action, PTFE forms fiber, the white lime fine particle that generates is constrained in the spider web of fiber filaments, forms above-mentioned white lime piece.In this case, hydration reaction heat is used for heating, compares with the preceding method that PTFE directly is added to white lime, has saved energy expenditure.In addition, PTFE is homodisperse at short notice, and this all helps reducing usage quantity and the treatment time of PTFE.

Slaked lime composition, particularly white lime fertilizer by the present invention obtains have direct effect to regulating soil acidity, and can keep the adjusting to soil acidity in over a long time.This composition is not only applicable to lime manure, is applicable to other purposes yet.For example, it can prevent to wait in the operation in neutralization especially effectively, owing to producing the environmental pollution that dust causes.

Following embodiment describes the present invention in detail,

Embodiment 1

The aqeous suspension (according to its solid situation, wherein the weight content of PTFE is 30%) of 0.17 gram and 0.83 gram PTFE is added in the 500 gram white limes (according to its solid situation, the PTFE weight content is respectively 0.01% and 0.05%), in mortar, simply mixes.Under 100 ℃ of temperature, heated 3 hours subsequently, in mortar, mixed 5 minutes immediately again.Apply compression shear power, make the PTFE fibrosis, prepare the white lime product of caking thus.Carry out the soil acidity regulation test together with the product of preparing with as the white lime of not handling that contrasts usefulness with PTFE.

The mixture that will contain the above-mentioned white lime of 7.5 grams sprays on 7 kilograms of soil of crossing with dry air, and speed is 20mm/cm every day ², after spraying for the first time, measure the 1st, 3,7,14 and 28 days P in soil H value and replaced calcium amount, the results are shown among Fig. 1 and Fig. 2.In each figure, the untreated white lime of the curve representation of solid rim symbol, the curve representation of open circle symbol contains the fertilizer of 0.01% PTFE, and the curve representation of triangle symbol contains the fertilizer of 0.05% PTFE.These figure show, the acidity adjustment performance and the conventional white lime fertilizer of white lime fertilizer that contains PTFE is similar, sprays the leaching loss that causes but it can reduce, and therefore can regulate soil acidity for a long time.

Reference example

In the super mixing tank (Kawada Seisakujo company limited) of 100 liters, put into the white lime that 13.0 kilograms of temperature have risen to 50 ℃, add subsequently 6.5 gram PTFE powder (based on white lime weight 0.05%) stirred for 30 seconds after, apply shearing force, but the fibrosis of PTFE is very slow and incomplete, so the white lime of product that obtains and routine much at one.Even restir more than 3 minutes, is also discovered less than any improvement.Next step be add again 19.5 the gram PTFE(all be 26 the gram, 0.2%), stirred 1 minute.At this moment form the suitably slaked lime composition of caking.This result shows, in the method, needs to add a large amount of PTFE, so that white lime suitably lumps.

Embodiment 2

10.0 kilograms of unslaked limes are placed in the super mixing tank, with PTFE aq suspension (according to its solid situation, the weight content of PTFE is 30%) hydration it, this suspension is that 21.7 gram PTFE fully are suspended in 4.5 kg of water.In this case, the amount of PTFE be the 0.065%(of unslaked lime weight be white lime weight 0.05%).In hydration reaction, intermittently stir twice, the time is 1 to 2 second.When the temperature of white lime drops to 90 ℃, with low speed material is applied 30 seconds of shearing force separately, form 13 kilograms of suitably slaked lime compositions of caking.Can see that thus the white lime particle improves and the amount of the required PTFE that lumps on request is less than consumption in the above-mentioned reference example greatly for forming.

Claims

1, has the slaked lime composition that has improved leaching character, its preparation method is characterised in that, tetrafluoroethylene is added to a kind of white lime or contains white lime and in the mixture of the hydrate of incinerating rhombspar, the lime particle that forms is wrapped in the microfilament net that tetrafluoroethylene forms.

2, the method for preparing slaked lime composition, it is characterized in that this method comprises the steps: the solid particulate of tetrafluoroethylene is dispersed in the water, the water yield will be enough to the mixture of a kind of unslaked lime of hydration or unslaked lime and burnt rhombspar, again the dispersion that generates is added in the mixture of this kind unslaked lime or unslaked lime and burnt rhombspar and stirs it, shear action by hydration heat and stirring operation, carry out the fibrosis of polytetrafluoroethylene granule, the white lime particle that generates is wrapped in the spider's thread net of tetrafluoroethylene formation, make white lime particle caking.