JPH0132199B2 - - Google Patents
Info
- Publication number
- JPH0132199B2 JPH0132199B2 JP55067581A JP6758180A JPH0132199B2 JP H0132199 B2 JPH0132199 B2 JP H0132199B2 JP 55067581 A JP55067581 A JP 55067581A JP 6758180 A JP6758180 A JP 6758180A JP H0132199 B2 JPH0132199 B2 JP H0132199B2
- Authority
- JP
- Japan
- Prior art keywords
- fertilizer
- coating
- phosphoric acid
- fertilizers
- water
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000003337 fertilizer Substances 0.000 claims description 76
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims description 47
- 238000000576 coating method Methods 0.000 claims description 34
- 239000011248 coating agent Substances 0.000 claims description 33
- 229910000147 aluminium phosphate Inorganic materials 0.000 claims description 24
- 239000000843 powder Substances 0.000 claims description 20
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 19
- 239000000126 substance Substances 0.000 claims description 14
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 7
- 229910021529 ammonia Inorganic materials 0.000 claims description 7
- 239000007795 chemical reaction product Substances 0.000 claims description 6
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical group [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 18
- 239000002245 particle Substances 0.000 description 13
- 238000010828 elution Methods 0.000 description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 10
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 9
- 235000011114 ammonium hydroxide Nutrition 0.000 description 9
- 239000000395 magnesium oxide Substances 0.000 description 9
- 230000000694 effects Effects 0.000 description 8
- 235000008733 Citrus aurantifolia Nutrition 0.000 description 7
- 235000011941 Tilia x europaea Nutrition 0.000 description 7
- 239000004571 lime Substances 0.000 description 7
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 6
- MXZRMHIULZDAKC-UHFFFAOYSA-L ammonium magnesium phosphate Chemical compound [NH4+].[Mg+2].[O-]P([O-])([O-])=O MXZRMHIULZDAKC-UHFFFAOYSA-L 0.000 description 6
- GVALZJMUIHGIMD-UHFFFAOYSA-H magnesium phosphate Chemical compound [Mg+2].[Mg+2].[Mg+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O GVALZJMUIHGIMD-UHFFFAOYSA-H 0.000 description 6
- 239000004137 magnesium phosphate Substances 0.000 description 6
- 229960002261 magnesium phosphate Drugs 0.000 description 6
- 229910000157 magnesium phosphate Inorganic materials 0.000 description 6
- 235000010994 magnesium phosphates Nutrition 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- 229910052698 phosphorus Inorganic materials 0.000 description 6
- 239000011574 phosphorus Substances 0.000 description 6
- 238000005507 spraying Methods 0.000 description 6
- 229910052567 struvite Inorganic materials 0.000 description 6
- 238000000034 method Methods 0.000 description 5
- 239000000377 silicon dioxide Substances 0.000 description 4
- 239000002689 soil Substances 0.000 description 4
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 3
- BPQQTUXANYXVAA-UHFFFAOYSA-N Orthosilicate Chemical compound [O-][Si]([O-])([O-])[O-] BPQQTUXANYXVAA-UHFFFAOYSA-N 0.000 description 3
- 239000011230 binding agent Substances 0.000 description 3
- YYRMJZQKEFZXMX-UHFFFAOYSA-N calcium;phosphoric acid Chemical compound [Ca+2].OP(O)(O)=O.OP(O)(O)=O YYRMJZQKEFZXMX-UHFFFAOYSA-N 0.000 description 3
- 238000004090 dissolution Methods 0.000 description 3
- 239000011777 magnesium Substances 0.000 description 3
- 229910052749 magnesium Inorganic materials 0.000 description 3
- HCWCAKKEBCNQJP-UHFFFAOYSA-N magnesium orthosilicate Chemical compound [Mg+2].[Mg+2].[O-][Si]([O-])([O-])[O-] HCWCAKKEBCNQJP-UHFFFAOYSA-N 0.000 description 3
- 239000000391 magnesium silicate Substances 0.000 description 3
- 229910052919 magnesium silicate Inorganic materials 0.000 description 3
- 235000019792 magnesium silicate Nutrition 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 239000002426 superphosphate Substances 0.000 description 3
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonia chloride Chemical compound [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 2
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 2
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 2
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 2
- 238000004176 ammonification Methods 0.000 description 2
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 2
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 2
- 235000011130 ammonium sulphate Nutrition 0.000 description 2
- 239000004202 carbamide Substances 0.000 description 2
- 239000011247 coating layer Substances 0.000 description 2
- 229910052681 coesite Inorganic materials 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 229910052906 cristobalite Inorganic materials 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- BHEPBYXIRTUNPN-UHFFFAOYSA-N hydridophosphorus(.) (triplet) Chemical compound [PH] BHEPBYXIRTUNPN-UHFFFAOYSA-N 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 150000002894 organic compounds Chemical class 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000011591 potassium Substances 0.000 description 2
- 229910052700 potassium Inorganic materials 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 235000012239 silicon dioxide Nutrition 0.000 description 2
- 229910052682 stishovite Inorganic materials 0.000 description 2
- 229910052905 tridymite Inorganic materials 0.000 description 2
- PAWQVTBBRAZDMG-UHFFFAOYSA-N 2-(3-bromo-2-fluorophenyl)acetic acid Chemical compound OC(=O)CC1=CC=CC(Br)=C1F PAWQVTBBRAZDMG-UHFFFAOYSA-N 0.000 description 1
- 235000019733 Fish meal Nutrition 0.000 description 1
- NWAHIIFFAROKNZ-UHFFFAOYSA-M N.O[Mg] Chemical compound N.O[Mg] NWAHIIFFAROKNZ-UHFFFAOYSA-M 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 235000019270 ammonium chloride Nutrition 0.000 description 1
- MYFXBBAEXORJNB-UHFFFAOYSA-N calcium cyanamide Chemical compound [Ca+2].[N-]=C=[N-] MYFXBBAEXORJNB-UHFFFAOYSA-N 0.000 description 1
- 239000003610 charcoal Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000003623 enhancer Substances 0.000 description 1
- 239000004467 fishmeal Substances 0.000 description 1
- 238000005469 granulation Methods 0.000 description 1
- 230000003179 granulation Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000011419 magnesium lime Substances 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 150000003016 phosphoric acids Chemical class 0.000 description 1
- 239000001103 potassium chloride Substances 0.000 description 1
- 235000011164 potassium chloride Nutrition 0.000 description 1
- OTYBMLCTZGSZBG-UHFFFAOYSA-L potassium sulfate Chemical compound [K+].[K+].[O-]S([O-])(=O)=O OTYBMLCTZGSZBG-UHFFFAOYSA-L 0.000 description 1
- 229910052939 potassium sulfate Inorganic materials 0.000 description 1
- 235000011151 potassium sulphates Nutrition 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 238000007873 sieving Methods 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- -1 that is Substances 0.000 description 1
- 150000003672 ureas Chemical class 0.000 description 1
Landscapes
- Fertilizers (AREA)
Description
本発明は肥料成分の１種以上を含有する粒状肥
料の表面が水に難溶性の不均一層によつて被覆さ
れている被覆粒状肥料に関する。
さらに詳しくは、粒状肥料表面がMgOとSiO2
を含有する無機物質粉末及び、りん酸液と該無機
物質粉末との反応生成物によつて被覆されてお
り、更に該反応生成物がアンモニアによつて処理
されていて、肥料成分の水中或いは土壌中への溶
出が抑制されている被覆粒状肥料に関する。
従来、水溶性の肥料、或いはそれら２種以上の
肥料塩を用いた複合肥料は一般に土壌中で比較的
速やかに溶出し、植物に利用される前に溶脱した
り、土壌中に固定されたりしてその利用率が低下
する。このような従来の肥料にみられる不利益を
改善するために、高分子有機化合物や水に難溶性
の無機物質粉末を用いて肥料を被覆してその溶出
を抑制する方法が提案されている。しかしなが
ら、高分子有機化合物を用いて肥料を被覆する場
合の最大の欠点はコストが高いことであり、一方
上記無機物質粉末で被覆する場合は被覆の不均一
さ、孔隙が多いために、多量に被覆してもなおそ
の効果は芳しくなかつた。さらに又、近年、肥料
粒子の表面をりん酸マグネシウムのスラリーで被
覆しながら、アンモニアと反応させて該表面にり
ん酸マグネシウムアンモニウムの被膜を形成せし
める方法（特開昭53−第2271号公報）が提案され
ている。この方法によれば、被覆におけるりん酸
マグネシウムが難溶性のりん酸マグネシウムアン
モニウムに変化されるので、肥料の表面に形成さ
れた被覆には耐水性が付与されるけれども、スラ
リーによる被覆形成によるために十分な被覆層の
厚さを得ることが困難であり、かつ被覆の緻密度
においても十分ではなく、したがつて、被覆工程
以降の製造工程、あるいは貯蔵、運搬、輸送等の
取り扱いにおいて肥料各粒子は接触・滑動・重圧
等に堪えることができず十分な緩効化を期待する
ことが出来ない。
又被覆肥料の一般的な難点としては、被覆の不
均一による肥料成分溶出率のばらつきが避けられ
ないことである。この被覆の不均一さを生ぜしめ
る原因の１つは母材肥料の粒度分布にある。すな
わち、肥料粒子の大きさが異ると、その表面積が
変り、被覆材の付着量に差が生ずる。その結果と
して、水中又は土壌中での溶出速度にばらつきが
生ずることになる。これを防ぐためには、母材肥
料の粒度を比較的狭い範囲に揃えることが必要と
なるけれども、これは技術的にも、経済的にも大
きな負担となる。
本発明者らは従来技術にみられる上記欠点を解
消すべく種々検討した結果、肥料粒子表面に溶成
りん肥料粉末のごときMgOとSiO2を含有する無
機物質粉末をりん酸を添加しながら被覆するとこ
れらの粉末の表面はりん酸により一部溶解し、生
成するりん酸マグネシウムが結合剤として働き、
これらの粉末を肥料粒子表面に付着させると同時
にこれら粉末が相互に密着されて、肥料粒子表面
にりん酸マグネシウムによつて一体となつたこれ
ら粉末の硬い被覆が生成すること、並びに、これ
らの被覆粒子をさらにアンモニア化することによ
つて上記結合剤の作用をしているりん酸マグネシ
ウムをりん酸マグネシウムアンモニウムに変化さ
せることにより、更に強固な被覆が生じ、その結
果肥料の溶出抑制効果が１段と高められること、
更に該無機物質中の珪酸塩はりん酸により一部が
ゲル状となつて被覆の間隙を埋める役割をするこ
と、更に又単にりん酸マグネシウムの被覆を形成
させたものよりも強固で安定な被覆となること、
及び溶出率のばらつきがより小さくなり、母材肥
料の粒度分布が比較的大きくても均質な被覆肥料
となること、を見出し本発明をなすに至つた。
本発明の目的は緩効性のすぐれた被覆粒状肥料
を提供するにある。
本発明の特徴は、肥料成分の少くとも１種を含
有する粒状肥料の表面が、該表面にりん酸と
MgO及びSiO2を含有する無機物質粉末とを適用
することにより生成する被覆物により被覆されて
おり、且つ該被覆物中のりん酸液と該無機物質粉
末との反応生成物がアンモニアで処理されている
ことを特徴とする被覆粒状肥料にある。
本発明でいう肥料成分としては特に限定される
ものではなく、硫安、塩安、硝安、尿素、尿素誘
導体、石灰窒素等の窒素質肥料、過燐酸石灰、重
過燐酸石灰、溶成燐肥等の燐酸質肥料、塩化カ
リ、硫酸カリ等のカリ質肥料、窒素、燐酸、カリ
のうち２成分以上を含む所謂複合肥料、炭カル、
石灰等の石灰質肥料、苦土石灰肥料、ケイカル肥
料等の他に、物油油粕及び魚粕等の有機質肥料を
指称し、その他に硝酸化成抑制剤、肥効増進剤を
も含みうるものである。
これらの肥料成分の少くとも１種以上を含有す
る粒状肥料は粒状化された肥料であればいかなる
制限もなく、更にいかなる造粒方式から得た粒状
肥料から成つていてもよく、特別の制限はない。
この粒状肥料表面に適用されるりん酸液は通常
P2O5濃度10％以上のりん酸液であつて、噴霧方
式で上記表面に適用される。特にP2O5濃度10％
以上のりん酸液を用いた場合にこれと併用される
上記無機物質粉末中に含まれる珪酸塩の一部がゲ
ル状となり形成された被覆の間隙を埋める役割を
するので好ましいが、P2O5濃度50％以上となる
と、りん酸液が粘稠となり過ぎて噴霧の際に良好
な分散が得られ難い。このりん酸液の噴霧量は該
肥料の粒子表面が湿める程度が好ましい。
かくしてりん酸液を粒状肥料表面に噴霧した後
にもしくは噴霧しながら該表面にMgOとSiO2を
含有する無機物質粉末を添加する。この無機物質
粉末としては溶成燐肥、苦土珪酸石灰または酸化
苦土若しくは水酸化苦土と珪砂の混合物等を例示
し得る。これら無機物質粉末は通常32メツシユ以
下に粉砕したものが用いられる。粒度が大きい時
反応速度が遅くなることと、被覆内の孔隙が多く
なる故に好ましくない。りん酸液と、MgO及び
SiO2含有無機物質粉末との添加を繰り返し行つ
て通常粒状肥料に対して約10重量％の被覆率以上
に被覆する。この被覆において、りん酸液と無機
物質に含まれるMgOとが反応し、これが他の反
応しない無機物質を接着し、極めて強固な被覆を
形成する。
上述のごとくして、りん酸液と前記無機物質粉
末の反応により付着生成した粒状肥料の被覆に対
して、更にアンモニア水又はアンモニアガスを接
触反応させて、被覆内の結合剤の部分、即ちりん
酸マグネシウムをりん酸マグネシウムアンモニウ
ムとすることによつて、水に対する溶解性が極め
て抑制された被覆を形成する。上記アンモニア化
にアンモニア水を使用するときは通常得られる28
重量％アンモニア水を用いるのが便利である。量
的には28％アンモニア水を用いる場合は粒状肥料
に対して通常１〜４重量％相当量の割合で添加す
る。
本発明による粒状肥料の被覆は単なるりん酸マ
グネシウムアンモニウム被覆ではなく、被覆材と
して用いる無機物質即ちMgOとSiO2の大部分を
骨格とし、その間隙をゲル状の珪酸塩が埋めると
同時に間隙をりん酸マグネシウムアンモニウムで
密着充填された不均一層からなり、硬度も高く、
肥料成分の溶出抑制効果も十分である。このよう
にして被覆層の溶解抑制性や密着性を改善し、安
定な被覆を形成した結果、母材肥料粒子の大きさ
や被覆方法に起因する被覆率のばらつきがあつて
も、肥料成分の溶出率のばらつきを相対的に小さ
くすることが可能となつた。又上記被覆の被覆率
を変えることによつて、その硬度および溶出抑制
効果を任意に高めることも出来る。更に上記被覆
率を30％以上としたときは乾燥することなく所定
の硬度と上記溶出抑制効果を得ることができる。
従つて、本発明の被覆粒状肥料は肥料成分の溶出
抑制効果において充分改良されて居り、コスト的
にも低減された緩効性肥料として広く使用するこ
とができるものである。
以下に実施例にもとづいて本発明を具体的に説
明する。なお、各実施例の部は特記しない限り重
量部を示す。
実施例 １
尿素３部、硫安58部、過りん酸石灰８部および
塩加22部をよく混合した後、皿形造粒機で適当に
加水をしながら造粒し、篩別後、粒径４mm〜７mm
の粒状肥料85部を得た。この粒状肥料40部に対し
て、P2O5濃度28％のりん酸液を噴霧したのち、
溶成りん肥粉末を添加反応させて被覆を形成させ
た。この操作を繰返して被覆率22％、31％、45％
となつた被覆粒状肥料を順次20部ずつ得た。次い
で各々の被覆粒状肥料に対してアンモニア水（28
％NH3）を２％相当量噴霧反応させ本発明の肥
料組成物を得た。製造１日後に、該肥料組成物10
ｇに対して200mlの蒸溜水を加え、30℃の恒温器
内に24時間静置したのち別し、液中の水溶性
窒素を測定し、水中24時間における溶出率を算出
した。アンモニア処理を施してない試料を対照肥
料とした。この結果を第１表に示す。
The present invention relates to a coated granular fertilizer in which the surface of a granular fertilizer containing one or more fertilizer components is covered with a non-uniform layer that is poorly soluble in water. In more detail, the surface of the granular fertilizer is MgO and SiO 2
and a reaction product of the phosphoric acid solution and the inorganic powder, and the reaction product is further treated with ammonia so that the fertilizer component is not contained in water or soil. This invention relates to a coated granular fertilizer whose elution into the inside is suppressed. Conventionally, water-soluble fertilizers or compound fertilizers using two or more types of fertilizer salts generally leach into the soil relatively quickly, and are often leached or fixed in the soil before being utilized by plants. and its utilization rate decreases. In order to improve the disadvantages of conventional fertilizers, methods have been proposed in which fertilizers are coated with a polymeric organic compound or a powder of an inorganic substance that is sparingly soluble in water to suppress their elution. However, the biggest disadvantage of coating fertilizers with high-molecular organic compounds is high cost, while coating them with the above-mentioned inorganic powders requires a large amount of coating due to non-uniformity and large pores. Even after coating, the effect was not good. Furthermore, in recent years, a method has been developed in which the surface of fertilizer particles is coated with a slurry of magnesium phosphate and reacted with ammonia to form a coating of magnesium ammonium phosphate on the surface (Japanese Patent Laid-Open Publication No. 2271/1983). Proposed. According to this method, the magnesium phosphate in the coating is changed to sparingly soluble magnesium ammonium phosphate, so the coating formed on the surface of the fertilizer is imparted with water resistance. It is difficult to obtain a sufficient thickness of the coating layer, and the density of the coating is also insufficient. cannot withstand contact, sliding, heavy pressure, etc., and cannot be expected to provide sufficient slowing effect. A general drawback of coated fertilizers is that variations in the rate of elution of fertilizer components due to non-uniform coating are unavoidable. One of the causes of this non-uniformity of coating is the particle size distribution of the base fertilizer. That is, when the size of fertilizer particles differs, the surface area changes, resulting in a difference in the amount of coating material deposited. As a result, variations in dissolution rate in water or soil will occur. In order to prevent this, it is necessary to align the particle size of the parent fertilizer within a relatively narrow range, but this poses a heavy burden both technically and economically. The present inventors conducted various studies in order to solve the above-mentioned drawbacks found in the conventional technology, and as a result, they coated the surface of fertilizer particles with an inorganic powder containing MgO and SiO 2 , such as dissolved phosphorus fertilizer powder, while adding phosphoric acid. Then, the surface of these powders is partially dissolved by phosphoric acid, and the magnesium phosphate produced acts as a binder.
At the same time as these powders are attached to the surface of the fertilizer particles, these powders are brought into close contact with each other to form a hard coating of these powders integrated with magnesium phosphate on the surface of the fertilizer particles; By further ammoniaizing the particles, the magnesium phosphate acting as the binder is changed to magnesium ammonium phosphate, resulting in an even stronger coating, which further improves the effect of suppressing fertilizer elution. to be enhanced,
Furthermore, the silicate in the inorganic substance partially becomes gel-like due to the phosphoric acid and fills the gaps in the coating, and furthermore, the coating is stronger and more stable than that simply formed by forming a coating of magnesium phosphate. to be,
The present inventors have discovered that the dispersion of the elution rate is further reduced, and that a uniform coated fertilizer can be obtained even if the particle size distribution of the base fertilizer is relatively large, leading to the present invention. An object of the present invention is to provide a coated granular fertilizer with excellent slow release properties. A feature of the present invention is that the surface of the granular fertilizer containing at least one fertilizer component is coated with phosphoric acid on the surface.
It is coated with a coating produced by applying an inorganic substance powder containing MgO and SiO 2 , and a reaction product of the phosphoric acid solution and the inorganic substance powder in the coating is treated with ammonia. It is a coated granular fertilizer characterized by: The fertilizer components referred to in the present invention are not particularly limited, and include ammonium sulfate, ammonium chloride, ammonium nitrate, urea, urea derivatives, nitrogenous fertilizers such as lime nitrogen, superphosphate lime, heavy superphosphate lime, dissolved phosphorus fertilizer, etc. phosphoric acid fertilizers, potassium fertilizers such as potassium chloride and potassium sulfate, so-called compound fertilizers containing two or more of nitrogen, phosphoric acid, and potassium, charcoal fertilizers,
In addition to calcareous fertilizers such as lime, magnesium lime fertilizers, silica fertilizers, etc., it refers to organic fertilizers such as oil cake and fish meal, and may also include nitrification inhibitors and fertilizer effect enhancers. . Granular fertilizers containing at least one of these fertilizer components are not subject to any restrictions as long as they are granulated fertilizers, and may also consist of granular fertilizers obtained from any granulation method, with no special restrictions. There isn't. The phosphoric acid solution applied to the surface of this granular fertilizer is usually
A phosphoric acid solution with a P 2 O 5 concentration of 10% or more, which is applied to the surface by spraying. Especially P2O5 concentration 10%
When the above-mentioned phosphoric acid solution is used, a part of the silicate contained in the above-mentioned inorganic substance powder used together with it becomes gelatinous and fills the gaps in the formed coating, so it is preferable to use P 2 O. 5 When the concentration exceeds 50%, the phosphoric acid solution becomes too viscous, making it difficult to obtain good dispersion during spraying. The spray amount of this phosphoric acid solution is preferably such that the surface of the particles of the fertilizer is moistened. Thus, after or while spraying the phosphoric acid solution onto the surface of the granular fertilizer, the inorganic substance powder containing MgO and SiO 2 is added to the surface. Examples of the inorganic substance powder include molten phosphorus fertilizer, magnesium silicate lime, oxidized magnesia, or a mixture of hydroxide magnesia and silica sand. These inorganic substance powders are usually used after being ground to 32 mesh or less. A large particle size is not preferred because the reaction rate becomes slow and the pores in the coating increase. Phosphoric acid solution, MgO and
By repeating the addition of SiO 2 -containing inorganic substance powder, the granular fertilizer is coated with a coverage of about 10% by weight or more. In this coating, the phosphoric acid solution reacts with the MgO contained in the inorganic substance, which bonds other non-reactive inorganic substances to form an extremely strong coating. As described above, the granular fertilizer coating formed by the reaction between the phosphoric acid solution and the inorganic substance powder is further subjected to a contact reaction with ammonia water or ammonia gas to remove the binder portion in the coating, that is, phosphorus. By using magnesium ammonium phosphate as the magnesium acid, a coating whose solubility in water is extremely suppressed is formed. When using aqueous ammonia for the above ammonification, usually obtained 28
It is convenient to use wt% ammonia water. In terms of quantity, when using 28% ammonia water, it is usually added in an amount equivalent to 1 to 4% by weight relative to the granular fertilizer. The coating of the granular fertilizer according to the present invention is not simply a magnesium ammonium phosphate coating, but has a skeleton made of most of the inorganic substances used as the coating material, namely MgO and SiO 2 , and gel-like silicate fills the gaps and at the same time fills the gaps with phosphorus. It consists of a non-uniform layer tightly packed with ammonium magnesium oxide, and has high hardness.
The effect of suppressing the elution of fertilizer components is also sufficient. As a result of improving the dissolution suppressing properties and adhesion of the coating layer and forming a stable coating, fertilizer components can be leached even if there are variations in coverage due to the size of the base fertilizer particles or coating method. It has become possible to relatively reduce the variation in rates. Further, by changing the coverage of the above-mentioned coating, the hardness and elution-inhibiting effect can be increased as desired. Further, when the coverage is set to 30% or more, the desired hardness and elution suppressing effect can be obtained without drying.
Therefore, the coated granular fertilizer of the present invention has been sufficiently improved in its effect of suppressing the elution of fertilizer components, and can be widely used as a slow-release fertilizer with reduced costs. The present invention will be specifically described below based on Examples. In addition, parts in each example indicate parts by weight unless otherwise specified. Example 1 After thoroughly mixing 3 parts of urea, 58 parts of ammonium sulfate, 8 parts of lime superphosphate, and 22 parts of salt, the mixture was granulated using a dish-shaped granulator while adding water appropriately, and after sieving, the particle size was determined. 4mm~7mm
85 parts of granular fertilizer were obtained. After spraying a phosphoric acid solution with a P 2 O 5 concentration of 28% on 40 parts of this granular fertilizer,
Molten phosphorus powder was added and reacted to form a coating. Repeat this operation to achieve coverage of 22%, 31%, and 45%.
20 parts of the coated granular fertilizer were sequentially obtained. Then add ammonia water (28
%NH 3 ) in an amount equivalent to 2% to obtain a fertilizer composition of the present invention. One day after production, the fertilizer composition 10
200 ml of distilled water was added to each g, and the mixture was allowed to stand in a thermostat at 30°C for 24 hours, then separated, the water-soluble nitrogen in the liquid was measured, and the dissolution rate in water for 24 hours was calculated. A sample without ammonia treatment was used as a control fertilizer. The results are shown in Table 1.
【表】
実施例
本例は本発明におけるアンモニア処理の効果を
確認するために行つたものである。
溶成燐肥（MgO15％、SiO220％）50部、苦土
珪酸石灰（Mg03％、SiO230％）50部に、P2O5濃
度20％のりん酸液80部を添加し、凝集物180部を
生成させたのち、凝集物の90部にアンモニア水
（28％NH3）2.5部を噴霧して反応物92.5部を得
た。凝集物と、この反応物について水溶性りん酸
と水溶性マグネシウムとを測定した結果を第２表
に示す。[Table] Example This example was carried out to confirm the effect of ammonia treatment in the present invention. 80 parts of a phosphoric acid solution with a P2O5 concentration of 20 % was added to 50 parts of dissolved phosphorous fertilizer (MgO15%, SiO2 20%) and 50 parts of magnesium silicate lime (Mg03%, SiO2 30%), After producing 180 parts of the aggregate, 2.5 parts of aqueous ammonia (28% NH 3 ) was sprayed onto 90 parts of the aggregate to obtain 92.5 parts of the reactant. Table 2 shows the results of measuring water-soluble phosphoric acid and water-soluble magnesium for the aggregate and this reaction product.
【表】
アンモニア水で処理した場合には、水溶性りん
酸は、アンモニア化をしてない場合に比べて減少
しており、難溶化反応が生起したことを示してい
る。又水溶性マグネシウムについても同様に、ア
ンモニア水処理により減少しており、りん酸マグ
ネシウムアンモニウムの生成が裏付けられてい
る。
実施例 ２
実施例１と同一の方法で得た被覆処理前の粒状
肥料40部に対し、P2O5濃度35重量％りん酸を噴
霧しながら、溶成燐肥と苦土珪酸石灰（鉱滓）の
等量混合物を添加反応させて付着させる操作を繰
返して、被覆率21％、33％、及び48％の被覆粒状
肥料をそれぞれ20部ずつを得た。次いで各々の被
覆肥料に対してアンモニア水（28％NH3）を３
重量％相当量噴霧し、本発明の被覆粒状肥料を得
た。製造１日後、実施例１と同様に水中24時間に
おける水溶性窒素を測定した。又実施例１と同様
にアンモニア処理をしない対照肥料についても溶
出率を測定した。結果を第３表に示す。[Table] When treated with aqueous ammonia, the amount of water-soluble phosphoric acid decreased compared to when no ammonification was performed, indicating that a reaction that made it difficult to solubilize occurred. Similarly, water-soluble magnesium was also reduced by aqueous ammonia treatment, supporting the production of magnesium ammonium phosphate. Example 2 40 parts of granular fertilizer before coating obtained by the same method as in Example 1 was mixed with melted phosphorous fertilizer and magnesium silicate lime (mine slag) while spraying phosphoric acid with a P 2 O 5 concentration of 35% by weight. 20 parts of each of coated granular fertilizers with coverage rates of 21%, 33%, and 48% were obtained by repeating the operation of adding and reacting equal amounts of mixtures of (3) and 48%. Then add 3 ml of ammonia water (28% NH 3 ) to each coated fertilizer.
A coated granular fertilizer of the present invention was obtained by spraying an amount equivalent to % by weight. One day after production, water-soluble nitrogen in water for 24 hours was measured in the same manner as in Example 1. Further, in the same manner as in Example 1, the elution rate was also measured for a control fertilizer that was not treated with ammonia. The results are shown in Table 3.
Claims (1)
の表面が、該表面にりん酸液とMgO及びSiO2を
含有する無機物質粉末とを適用することにより生
成する反応生成物により被覆されており、且つ該
被覆物中のりん酸と該無機物質粉末との反応生成
物がアンモニアで処理されていることを特徴とす
る被覆粒状肥料。1. The surface of a granular fertilizer containing at least one fertilizer component is coated with a reaction product produced by applying a phosphoric acid solution and an inorganic powder containing MgO and SiO 2 to the surface. A coated granular fertilizer characterized in that a reaction product of phosphoric acid and the inorganic substance powder in the coating is treated with ammonia.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6758180A JPS56164090A (en) | 1980-05-21 | 1980-05-21 | Coated granular fertilizer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP6758180A JPS56164090A (en) | 1980-05-21 | 1980-05-21 | Coated granular fertilizer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS56164090A JPS56164090A (en) | 1981-12-16 |
| JPH0132199B2 true JPH0132199B2 (en) | 1989-06-29 |
Family
ID=13349027
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP6758180A Granted JPS56164090A (en) | 1980-05-21 | 1980-05-21 | Coated granular fertilizer |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS56164090A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| ES2156746B1 (en) * | 1999-07-20 | 2002-05-01 | Inabonos Sa | NITROGEN FERTILIZER, CONTAINING UREIC NITROGEN, AMMONIC AND ORGANIC NITRIC, GRADUAL SOLUBILITY AND PROGRESSIVE NITRIFICATION, AND METHOD OF OBTAINING. |
| JP4889848B2 (en) * | 2000-09-01 | 2012-03-07 | エス・キュー・エム ジャパン株式会社 | Granular fertilizer |
-
1980
- 1980-05-21 JP JP6758180A patent/JPS56164090A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS56164090A (en) | 1981-12-16 |
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