JPS629526B2 - - Google Patents
Info
- Publication number
- JPS629526B2 JPS629526B2 JP260780A JP260780A JPS629526B2 JP S629526 B2 JPS629526 B2 JP S629526B2 JP 260780 A JP260780 A JP 260780A JP 260780 A JP260780 A JP 260780A JP S629526 B2 JPS629526 B2 JP S629526B2
- Authority
- JP
- Japan
- Prior art keywords
- lead
- monoxide
- cubic
- particles
- nitrate
- 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
- YEXPOXQUZXUXJW-UHFFFAOYSA-N oxolead Chemical compound [Pb]=O YEXPOXQUZXUXJW-UHFFFAOYSA-N 0.000 claims description 117
- 229910000464 lead oxide Inorganic materials 0.000 claims description 48
- 238000000034 method Methods 0.000 claims description 26
- 239000002245 particle Substances 0.000 claims description 25
- 239000008187 granular material Substances 0.000 claims description 20
- RLJMLMKIBZAXJO-UHFFFAOYSA-N lead nitrate Chemical compound [O-][N+](=O)O[Pb]O[N+]([O-])=O RLJMLMKIBZAXJO-UHFFFAOYSA-N 0.000 claims description 17
- PAWQVTBBRAZDMG-UHFFFAOYSA-N 2-(3-bromo-2-fluorophenyl)acetic acid Chemical compound OC(=O)CC1=CC=CC(Br)=C1F PAWQVTBBRAZDMG-UHFFFAOYSA-N 0.000 claims description 15
- 239000002002 slurry Substances 0.000 claims description 15
- 238000004519 manufacturing process Methods 0.000 claims description 13
- 239000012736 aqueous medium Substances 0.000 claims description 8
- 238000010304 firing Methods 0.000 claims description 8
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 claims description 7
- XMFOQHDPRMAJNU-UHFFFAOYSA-N lead(ii,iv) oxide Chemical compound O1[Pb]O[Pb]11O[Pb]O1 XMFOQHDPRMAJNU-UHFFFAOYSA-N 0.000 claims description 6
- 230000003647 oxidation Effects 0.000 claims description 2
- 238000007254 oxidation reaction Methods 0.000 claims description 2
- 238000005469 granulation Methods 0.000 description 14
- 230000003179 granulation Effects 0.000 description 14
- 239000011362 coarse particle Substances 0.000 description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 12
- 239000000843 powder Substances 0.000 description 11
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 10
- 239000013078 crystal Substances 0.000 description 8
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 7
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 7
- 239000000203 mixture Substances 0.000 description 7
- 229910052760 oxygen Inorganic materials 0.000 description 7
- 239000001301 oxygen Substances 0.000 description 7
- 239000002994 raw material Substances 0.000 description 7
- 229910021529 ammonia Inorganic materials 0.000 description 5
- 150000002611 lead compounds Chemical class 0.000 description 5
- HTUMBQDCCIXGCV-UHFFFAOYSA-N lead oxide Chemical compound [O-2].[Pb+2] HTUMBQDCCIXGCV-UHFFFAOYSA-N 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 239000000428 dust Substances 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 238000010298 pulverizing process Methods 0.000 description 4
- 238000005096 rolling process Methods 0.000 description 4
- 239000011787 zinc oxide Substances 0.000 description 4
- 238000001125 extrusion Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- JQJCSZOEVBFDKO-UHFFFAOYSA-N lead zinc Chemical compound [Zn].[Pb] JQJCSZOEVBFDKO-UHFFFAOYSA-N 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 238000001694 spray drying Methods 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 235000013372 meat Nutrition 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- -1 (OH) 10 Chemical compound 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005119 centrifugation Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000009837 dry grinding Methods 0.000 description 1
- 238000010410 dusting Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000005355 lead glass Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 239000012452 mother liquor Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000000879 optical micrograph Methods 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 230000003449 preventive effect Effects 0.000 description 1
- 239000006077 pvc stabilizer Substances 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000011882 ultra-fine particle Substances 0.000 description 1
Landscapes
- Crystals, And After-Treatments Of Crystals (AREA)
Description
本発明は、新規な酸化鉛粒状物の製造法に関す
るもので、より詳細には、従来の機械的造粒手段
に代つて、化学的造粒手段によつて立方体の形状
の酸化鉛粒状物を製造する方法に関する。
一酸化鉛(リサージ)及び四三酸化鉛(光明
丹)は、防錆剤、顔料、光導体、塩化ビニル樹脂
安定剤等としてそれ自体有用な物質であると共
に、鉛硝子、釉薬、蓄電池、塩ビ安定剤、黄鉛、
エレクトロセラミツク等の原料としても有用な物
質であるが、これらの酸化鉛はその粒子径が一般
に3乃至7μmの範囲にあり、その取扱いに際し
て粉塵飛散を生じ易く、これにより作業環境が汚
染されるという問題を生じる。また、これを解消
するためには、酸化鉛を取扱う全ての部分で発生
する鉛粉塵を含む排気を高価な集塵操作に付さな
ければならないという不便がある。
この問題を改善するために、酸化鉛を粒状物に
成形し、これを種々の用途に供給することが既に
行われている。しかしながら公知の酸化鉛粒状物
の製造方法は、酸化鉛の粉末を、転動造粒、押出
造粒、噴霧乾燥造粒等の機械的手段で造粒する
か、或いは酸化鉛の前駆物質である亜酸化鉛粉末
を前述した造粒手段で造粒し、この粒状物を酸素
含有雰囲気で焼成することから成つている。公知
の酸化鉛の粒状物は何れも機械的造粒物であるこ
とに関連して、粒状物相互の接触乃至は摩擦によ
り粉化する傾向が大であり、粒状物としての流動
性も概して低いという点で未だ十分満足し得るも
のではなかつた。
本発明者等は、酸化鉛を化学的に粒状化する新
規方法を見出した。即ち、本発明者等は、一辺の
長さが0.05mm以上の塩基性硝酸鉛の立方晶粒子を
焼成するときには、この立方体の形状を実質上そ
のまま維持した形態の一酸化鉛或いは四三酸化鉛
の粒子が形成され、これらの酸化鉛粒状物は、公
知の酸化鉛粒状物等に比して顕著に優れた耐摩耗
性(耐粉化性)、流動性等を示すことを見出し
た。
〓〓〓〓
この塩基性硝酸鉛の粗大立方晶粒子は、好適に
は一酸化鉛と一酸化鉛当り0.2乃至2.0モル倍の硝
酸アンモニウムとを水性媒体中で且つ最終スラリ
ーのPHが4.0乃至10.0となる条件下に混合し、こ
のスラリーを放置して塩基性硝酸鉛の立方晶粒子
を成長させることにより得られる。
本発明による酸化鉛粒状物は、塩基性硝酸鉛の
粗大立方晶そのものを前駆物質とし、しかもその
焼成により形成されるため、粒子の圧縮強度、摩
耗強度等が機械的造粒法によるものに比して著し
く大であり、苛酷な取扱いを行つた場合にも粉化
する傾向が殆んどない。実際的な値として、後述
する例の方法で測定して、従来の機械的造粒法に
よるものは、90%以上の粉化度を示すのに対し
て、本発明による立方体粒状物は、10%よりも
小、特に5%以下の粉化度を示すにすぎないので
ある。かくして、本発明による酸化鉛粒状物を使
用すれば、取扱い時における酸化鉛粉塵の発生を
著しく抑制し得ることが明白であろう。
のみならず、本発明による酸化鉛粒状物は、第
1図の顕微鏡写真(倍率:50倍)から明らかな通
り、明確な立方体から成り、しかも一辺の長さが
0.05mm以上、特に0.1mm以上の粗大粒子であり、
更にその粒度分布も極めて均斉であることに関連
して、従来の酸化鉛粒状物に比して勝るとも劣ら
ない優れた流動性を示す。
のみならず、本発明方法は、酸化鉛を機械的に
造粒するという手段は一切必要としないため、高
い能率でしかも大規模に酸化鉛粒状物を製造し得
るという製造操作上の顕著な利点がある。
更に、副原料として使用する硝酸アンモンは、
塩基性硝酸鉛の生成時にアンモニウム成分を回収
し、一方鉛成分に随伴する硝酸分は、焼成時に発
生するガスをアンモニアに吸収させることによ
り、結局硝酸アンモンとして回収されるから、非
常に経済的に、酸化鉛粒状物を製造し得ることが
明白である。
本発明において、原料として使用する一酸化鉛
としては、それ自体公知の乾式法一酸化鉛、即ち
金属鉛粒をチユーブミル内に入れ、これに空気を
吹込み、摩擦と空気中の酸素による発熱を伴なう
酸化とによつて金属鉛粒の表面から亜酸化鉛
(PbOx,x=0.3〜0.7、一般に鉛粉と呼ばれてい
る)の粉末を剥離、粉化せしめ、この亜酸化鉛粉
末を前記チユーブ・ミルから空気と共に取出し、
次いで別の反応容器内で加熱酸化して赤色乃至黄
色の一酸化鉛としたものが好適に使用される。こ
の一酸化鉛の粒径は可及的に微細であることが望
ましく、10μm以下、特に5μm以下のものが好
適に使用される。
一酸化鉛としては、本発明者等の提案にかかる
湿式法乃至は活性一酸化鉛(米国特許第4117104
号明細書参照)をも使用することができる。
本発明において、塩基性硝酸鉛の粗大立方晶粒
子を製造するには、先ず、この一酸化鉛と、一酸
化鉛当り0.2乃至2.0モル倍、特に1.0乃至1.7モル
の硝酸アンモンとを水性媒体中で混合する。硝酸
アンモンの量が上記範囲よりも少ないときには、
塩基性硝酸鉛の収率が低下するだけではなく、粗
大な立方晶の形成も困難となる。また、この量が
上記範囲よりも多くなると、立方晶以外の塩基性
硝酸鉛が生成するようになる。
一酸化鉛と硝酸アンモンとの混合は、一酸化鉛
の水性スラリーと硝酸アンモンの水溶液とを添加
混合することにより好適に行われる。水性媒体の
量は、用いる硝酸アンモンを完全に溶解するに足
る量であることが望ましいが、勿論、少量の水性
媒体と溶解量よりも多い硝酸アンモンとの組合せ
を使用することもできる。
一酸化鉛と硝酸アンモンとを水性媒体中で混合
する際、最終水性スラリーのPHが4.0乃至10.0特
に7.0乃至8.0の範囲となるような条件を選ぶこと
も、粗大立方晶の塩基性硝酸鉛を形成させる上で
重要である。このPHが上記範囲よりも高いときに
は、やはり明確な立方晶の粗大粒子を形成させる
ことが困難となり、一方このPHが上記範囲よりも
低いときには、立方晶塩基性硝酸鉛の収率が低下
することになる。
スラリーの最終PHの調節は、スラリーを加熱し
て、遊離するアンモニアを水性媒体から追出すこ
とにより容易に行い得る。この目的のためには、
スラリーを50℃以上、特に80℃以上の温度に加熱
するのが望ましい。加熱時間は、液のPHが上記範
囲となるように適宜定め得るが、一般には1乃至
10時間の範囲が好適である。一酸化鉛と硝酸アン
モンとを、水性媒体中で最初から上記温度で混合
することもできるが、操作の点では、最初に、室
温或いは50℃よりも低い加温下に両者の混合を行
〓〓〓〓
い、次いで形成される均質化したスラリーを前記
温度に加熱するのが望ましい。
かくして形成される塩基性硝酸鉛の水性スラリ
ーを放置し、一辺の長さが0.05mm以上、特に0.1
mm以上の立方晶粗大粒子を晶出させる。通常一晩
の放置で晶出が完了し、殆んど100%に近い収率
で立方晶粗大粒子が得られる。
この粗大粒子を、過、遠心分離等により母液
から分離し、必要により水洗した後、乾燥する。
塩基性硝酸鉛の粗大立方晶粒子を焼成して立方
体の形状の一酸化鉛或いは四三酸化鉛粒子とす
る。即ち、この焼成を400乃至500℃の温度で且つ
空気等の酸素含有雰囲気中で焼成すると、四三酸
化鉛(光明丹)の粗大立方体粒子が得られ、この
光明丹の粗大粒子を600〜650℃の温度で焼成する
と、一酸化鉛の立方体粗大粒子が得られる。勿
論、二段法で一酸化鉛の粗大粒子を製造する代わ
りに、上記温度に一段で焼成し、一酸化鉛の立方
体粒状物を製造することもできる。
本発明を次の例で説明する。
参考例 1
湿式法による酸化鉛(以下、本実施例において
は、湿式法により調製された酸化鉛をW―PbOと
略記することがある。)の製造法としては米国特
許第4117104号明細書に記載された方法に準拠し
て製造した。即ち8.3乃至9.2g/c.c.の密度、0.2μ
以下の数平均粒径、波数1400乃至1410cm-1に赤外
線吸収ピーク及び、94%以上の無水クロム酸反応
率を有する一酸化鉛の製造法について概説する。
直径2乃至7mmの金属鉛(電気鉛純度99.99
%)の粒状物200Kgを回転式ステンレス製チユー
ブミル(内径34.5cm、長さ130cm、内容積約120
)に入れ、これに水30および酸素(2Kgゲー
ジ圧)を充填し、このチユーブミルを回転させる
ことにより、水で湿潤された金属鉛の一部が水面
よりも上方の酸素気相中に遠心力で押揚げられ、
金属鉛粒の周りの水の超薄膜層が酸素を吸収し、
ここで一酸化鉛を生成し、且つ金属鉛の粒状物が
水中で相互に摩擦し合つて生成した一酸化鉛の超
微粒子が水中に分散し、濃度PbO33.5g/100ml
の分散液(試料番号W―PbO―1)が得られた。
ここに得られた湿式法一酸化鉛スラリーは、
過し、次いで約80℃で乾燥した後粉砕して湿式法
一酸化鉛乾燥粉末品(試料番号W―PbO―2)を
調製した。
参考例 2
乾式による一酸化鉛(以下、本実施例において
は、乾式法により調製された酸化鉛をD―PbOと
略記することがある。)の製造法としては特公昭
37―11801号公報に記載の方法に準拠して製造し
た。まず、電気鉛のインゴツトを鉛成型機を用い
て直径2.5cm×長さ2.0cmの円柱状に成型した後、
島津源蔵氏の研究報告である機械学会誌28巻(No.
100)489〜516頁(1925)に記載されている謂る
島津式鉛粉法に準拠して回転ミル中で乾式粉砕方
式で金属鉛を粉砕しつつ、暗灰緑色の亜酸化鉛粉
末(謂る鉛粉)を製造した。次いでここに回収し
た亜酸化鉛粉末を回転炉に入れて酸素を加えて撹
拌下に燃焼させ、約630〜720℃の温度条件下で酸
化し亜酸化鉛の燃焼熱による温度上昇を測定して
いて最早燃焼による温度上昇が見られなくなるや
いなや、これを冷却用チヤンバーに急速に払い出
し冷却すると黄色の顆粒状の酸化鉛が得られる。
次いでこの黄色の顆粒状の酸化鉛を粉砕し、気体
サイクロン方式により分級してオレンジ色を呈し
た黄色の一酸化鉛粉末(原料番号D―PbO)を調
製した。
実施例
酸化鉛の粗大粒子製造について説明する。
鉛分原料としては、上記参考例で調製した湿式
ならびに乾式法による酸化鉛3種類を選んだ。
粗大粒子の製造方法としては、各酸化鉛をPbO
換算で300g/濃度になるように水に分散し、
均一な酸化鉛の水性スラリーを調製した後、この
水性スラリーを約40℃に加熱し、撹拌しながらこ
れに10Mol/濃度に調製された硝酸アンモニウ
ム溶液を(NO3 -/PbOのモル割合で0.2乃至2.0の
範囲の量)ゆつくり注加し、注加後40℃でさらに
30分間撹拌を続け、酸化鉛に硝酸アンモニウムを
充分に慣ました後、80〜90℃に加熱して含まれる
アンモニア分を揮散させ、この反応液のPHが7.5
になるまで加熱を続けた。この間5時間を要し
た。その後この反応液を室温に放置し生成した粗
大結晶を過した。
上記の処理で得られる鉛化合物は、粗大立方体
状の塩基性硝酸鉛(Pb(NO3)(OH),Pb3
(NO3)(OH)5等)であつた。次いで得られた鉛
化合物を130℃で2時間乾燥し、低温乾燥による
〓〓〓〓
試料を得た。この乾燥により鉛化合物は、その塩
基度が変化し、Pb3(NO3)(OH)5,Pb7(NO3)4
(OH)10等の塩基性硝酸鉛になるが、粗大立方状
の形状には変化がなかつた。さらに、ここに得た
低温乾燥による試料を450℃及び600℃でそれぞれ
2時間焼成して450℃及び600℃焼成の試料を得
た。
この焼成により鉛化合物は四三酸化及び一酸化
鉛に変化するが、粗大立方体状の形状には変化が
なかつた。
なお、上記製造条件においてその条件内容を変
えた所は第1表に表示した内容に従つた。
ここに製造した粗大粒子の各物性について下記
方法により測定した。
a 粒の密度
ピクノメーターを用い常法により測定した。
b 比容積(ml/g)
1分間15回転、30回落下衝撃を行う石山科学器
械製作所製の比容積試験器を用いて20分間落下衝
撃を行い、測定した。
c 数平均粒径(μ)
光学顕微鏡を用い、視野40倍の倍率で観察し、
粒子の大きさを測定し、その各粒子の大きさの数
平均より、その平均粒子径(μ)を求めた。
d 結晶型
理学電機(株)製のX線自記回折装置を用い、粉末
測定法により測定した。
なお、結晶型は下記の略記号を用いて表示し
た。
リサージ型―酸化鉛:L―PbO
マシコツト型―酸化鉛:M―PbO
四三酸化鉛:Pb3O4
塩基性硝酸鉛:BNL
BNLは、Pb(NO3)(OH),Pb3(NO3)
(OH)5,Pb7(NO3)4(OH)10の3種を総称し
た。
e 安息角(度)
高林理化(株)製粉体安息角測定装置を用いて測定
した。
f 粉化度(%)
粒状試料100gを内容積140mlのプラスチツク製
円筒容器の中に採り、横振り往復運動する振盪機
(振幅40mm、振盪数300R.P.M.)に固定し、10分
間振盪した後回収し、150メツシユ篩いで分級
し、その篩通過量A(g)より粉化度を求めた。
以上の結果を第1表に併せて表示する。
なお、比較例として、本実施例の原料に用いた
湿式及び乾式法酸化鉛を常法により転動造粒押出
造粒、噴霧乾燥造粒し、酸素雰囲気中で600℃で
2時間焼成した場合及び米国特許第3623838号明
細書記載の方法に従つて顆粒状の酸化鉛を製造し
た場合についてそれぞれ本実施例と同様にして各
物性について測定し、その結果を第2表に併せ表
示する。
酸化鉛の転動造粒としては、各酸化鉛を回転円
盤皿式の転動造粒機に供給し、皿を回転させなが
ら、水を噴霧する方法によつた。
押出し造粒は、各酸化鉛1Kgに水60mlを加え混
練し、均質な湿潤状態とした後、肉挽機型の造粒
機を用いて径2mmの円柱状に押出す方法によつ
た。又、噴霧乾燥造粒は各酸化鉛1Kgに水400ml
を加え均質ペースト状とした後デイスク型噴霧乾
燥器を用い250℃温風下で乾燥する方法によつ
た。
さらに、米国特許第3623838号明細書記載の方
法に従つて造粒としては、参考例2に記載の方法
で調製した亜酸化鉛(謂る鉛粉)1Kgに水60mlを
加え、混練して均質湿潤状態とした後、肉挽機型
の造粒機を用いて径2mmの円柱状に押出す方法に
よつた。得られた各粒状物は必要により130℃で
2時間乾燥した後、550〜600℃で2時間焼成し
た。得られた各粒状焼成物を必要により粗砕し60
メツシユと150メツシユの篩を用いて分級し、246
乃至104μの間の顆粒状酸化鉛を得た(試料番号
H―1〜H―7)
〓〓〓〓
The present invention relates to a novel method for producing lead oxide granules, and more particularly, the present invention relates to a novel method for producing lead oxide granules, and more particularly, to produce cubic-shaped lead oxide granules by chemical granulation means instead of conventional mechanical granulation means. Relating to a method of manufacturing. Lead monoxide (Resurge) and trilead tetroxide (Komeitan) are useful substances in themselves as rust preventives, pigments, light conductors, vinyl chloride resin stabilizers, etc., and are also used in lead glass, glazes, storage batteries, PVC stabilizer, yellow lead,
These lead oxides are useful materials as raw materials for electroceramics, etc., but the particle size of these lead oxides is generally in the range of 3 to 7 μm, and when they are handled, they tend to generate dust, which contaminates the working environment. cause problems. Moreover, in order to solve this problem, there is the inconvenience that the exhaust gas containing lead dust generated in all parts handling lead oxide must be subjected to an expensive dust collection operation. To remedy this problem, lead oxide has already been formed into granules and supplied to various applications. However, known methods for producing lead oxide granules include granulating lead oxide powder by mechanical means such as rolling granulation, extrusion granulation, and spray drying granulation, or using a lead oxide precursor. The method consists of granulating zinc oxide powder using the above-mentioned granulating means and firing the granulated material in an oxygen-containing atmosphere. Since all known lead oxide granules are mechanically granulated, they have a strong tendency to powder due to mutual contact or friction, and the fluidity of the granules is generally low. In this respect, I was still not completely satisfied. The inventors have discovered a new method of chemically granulating lead oxide. That is, the present inventors believe that when firing cubic crystal particles of basic lead nitrate with a side length of 0.05 mm or more, lead monoxide or trilead tetroxide in a form that substantially maintains the cubic shape. It has been found that these lead oxide granules exhibit significantly superior abrasion resistance (dusting resistance), fluidity, etc., as compared to known lead oxide granules. 〓〓〓〓
The coarse cubic particles of basic lead nitrate are preferably prepared by mixing lead monoxide and ammonium nitrate in an amount of 0.2 to 2.0 moles per lead monoxide in an aqueous medium under conditions such that the pH of the final slurry is 4.0 to 10.0. It is obtained by mixing and leaving this slurry to grow cubic grains of basic lead nitrate. The lead oxide granules according to the present invention use the coarse cubic crystals of basic lead nitrate as a precursor and are formed by sintering, so the compressive strength, abrasion strength, etc. of the particles are compared to those produced by mechanical granulation. It is extremely large in size and has little tendency to powder even when subjected to harsh handling. As a practical value, the conventional mechanical granulation method shows a degree of pulverization of more than 90%, as measured by the example method described below, whereas the cubic granules according to the present invention have a degree of pulverization of 10% or more. %, especially 5% or less. It will thus be clear that by using the lead oxide granules according to the invention, the generation of lead oxide dust during handling can be significantly reduced. Furthermore, as is clear from the micrograph in Figure 1 (magnification: 50x), the lead oxide granules according to the present invention consist of a clear cube, and the length of each side is
Coarse particles of 0.05 mm or more, especially 0.1 mm or more,
Furthermore, in connection with its extremely uniform particle size distribution, it exhibits excellent fluidity that is comparable to that of conventional lead oxide granules. Furthermore, since the method of the present invention does not require any means for mechanically granulating lead oxide, it has the remarkable advantage of manufacturing lead oxide granules with high efficiency and on a large scale. There is. Furthermore, ammonium nitrate used as an auxiliary raw material is
The ammonium component is recovered when basic lead nitrate is produced, and the nitric acid accompanying the lead component is eventually recovered as ammonium nitrate by absorbing the gas generated during firing into ammonia, making it extremely economical. It is clear that lead oxide granules can be produced. In the present invention, the lead monoxide used as a raw material is produced by a known dry method, that is, metal lead particles are placed in a tube mill and air is blown into the tube mill to reduce heat generation due to friction and oxygen in the air. Through the accompanying oxidation, the powder of lead zinc oxide ( PbO is removed from the tube mill along with air,
The lead monoxide is then heated and oxidized in a separate reaction vessel to form red to yellow lead monoxide, which is preferably used. It is desirable that the particle size of this lead monoxide is as fine as possible, and particles of 10 μm or less, especially 5 μm or less are preferably used. As lead monoxide, the wet method proposed by the present inventors or activated lead monoxide (US Patent No. 4117104
(see specification) can also be used. In the present invention, in order to produce coarse cubic particles of basic lead nitrate, first, this lead monoxide and ammonium nitrate of 0.2 to 2.0 times the lead monoxide, particularly 1.0 to 1.7 moles per lead monoxide, are mixed in an aqueous medium. Mix with When the amount of ammonium nitrate is less than the above range,
Not only does the yield of basic lead nitrate decrease, but it also becomes difficult to form coarse cubic crystals. Moreover, if this amount exceeds the above range, basic lead nitrate other than cubic crystals will be produced. Mixing of lead monoxide and ammonium nitrate is suitably performed by adding and mixing an aqueous slurry of lead monoxide and an aqueous solution of ammonium nitrate. It is desirable that the amount of the aqueous medium is sufficient to completely dissolve the ammonium nitrate used, but of course a combination of a small amount of the aqueous medium and more ammonium nitrate than the dissolved amount can also be used. When mixing lead monoxide and ammonium nitrate in an aqueous medium, it is also possible to select conditions such that the pH of the final aqueous slurry is in the range of 4.0 to 10.0, especially 7.0 to 8.0. It is important for formation. When this PH is higher than the above range, it becomes difficult to form clear cubic coarse particles, while when this PH is lower than the above range, the yield of cubic basic lead nitrate decreases. become. Adjustment of the final PH of the slurry can be easily accomplished by heating the slurry to drive liberated ammonia from the aqueous medium. For this purpose,
It is desirable to heat the slurry to a temperature of 50°C or higher, especially 80°C or higher. The heating time can be determined as appropriate so that the pH of the liquid falls within the above range, but generally it is between 1 and 2.
A range of 10 hours is preferred. It is also possible to mix lead monoxide and ammonium nitrate in an aqueous medium from the beginning at the above temperature, but in terms of operation, first mix them at room temperature or at a temperature lower than 50°C. 〓〓〓
It is then desirable to heat the homogenized slurry formed to said temperature. The aqueous slurry of basic lead nitrate thus formed is left to stand, with a side length of 0.05 mm or more, especially 0.1
Crystallize cubic coarse particles of mm or more. Crystallization is usually completed after standing overnight, and cubic coarse particles can be obtained with a yield close to 100%. The coarse particles are separated from the mother liquor by filtration, centrifugation, etc., washed with water if necessary, and then dried. Coarse cubic particles of basic lead nitrate are fired to form cube-shaped lead monoxide or trilead tetroxide particles. That is, when this firing is performed at a temperature of 400 to 500°C and in an oxygen-containing atmosphere such as air, coarse cubic particles of trilead tetroxide (Komeitan) are obtained, and these coarse particles of Komyotan are When calcined at a temperature of °C, cubic coarse particles of lead monoxide are obtained. Of course, instead of producing coarse particles of lead monoxide using the two-stage method, it is also possible to produce cubic particles of lead monoxide by firing at the above-mentioned temperature in one stage. The invention is illustrated by the following example. Reference Example 1 A method for producing lead oxide by a wet method (hereinafter, in this example, lead oxide prepared by a wet method may be abbreviated as W-PbO) is described in U.S. Patent No. 4117104. Manufactured according to the method described. i.e. density of 8.3 to 9.2 g/cc, 0.2μ
A method for producing lead monoxide having a number average particle size, an infrared absorption peak at a wave number of 1400 to 1410 cm -1 , and a chromic anhydride reaction rate of 94% or more will be outlined below. Metal lead with a diameter of 2 to 7 mm (electrolytic lead purity 99.99
%) granules in a rotary stainless steel tube mill (inner diameter 34.5cm, length 130cm, internal volume approx. 120cm)
) and fill it with water and oxygen (2 kg gauge pressure), and by rotating this tube mill, a part of the metal lead moistened with water is moved into the oxygen gas phase above the water surface by centrifugal force. pushed up by
The ultra-thin layer of water around the metal lead grains absorbs oxygen,
Lead monoxide is generated here, and the ultrafine particles of lead monoxide that are generated when the metallic lead particles rub against each other in the water are dispersed in the water, resulting in a concentration of PbO33.5g/100ml.
A dispersion liquid (sample number W-PbO-1) was obtained. The wet method lead monoxide slurry obtained here is
The powder was filtered and then dried at about 80° C. and then ground to prepare a wet lead monoxide dry powder product (sample number W-PbO-2). Reference Example 2 As a method for producing lead monoxide by a dry method (hereinafter, in this example, lead oxide prepared by a dry method may be abbreviated as D-PbO), the
It was produced according to the method described in Publication No. 37-11801. First, an electrolytic lead ingot was molded into a cylinder with a diameter of 2.5 cm and a length of 2.0 cm using a lead molding machine.
Genzo Shimazu's research report, Journal of the Japan Society of Mechanical Engineers, Volume 28 (No.
100) According to the so-called Shimadzu lead powder method described on pages 489-516 (1925), metallic lead is ground using a dry grinding method in a rotary mill, and dark gray-green lead zinc oxide powder (so-called lead powder). The zinc oxide powder collected here is then placed in a rotary furnace, mixed with oxygen, and burnt with stirring. Oxidized at a temperature of approximately 630 to 720 degrees Celsius, the temperature rise due to the heat of combustion of the zinc oxide is measured. As soon as the temperature no longer increases due to combustion, it is rapidly discharged into a cooling chamber and cooled, yielding yellow granular lead oxide.
Next, this yellow granular lead oxide was crushed and classified using a gas cyclone method to prepare an orange yellow lead monoxide powder (raw material number D-PbO). Example Production of lead oxide coarse particles will be explained. As the lead raw materials, three types of lead oxides prepared in the above reference examples by wet and dry methods were selected. As a method for producing coarse particles, each lead oxide is
Dispersed in water to a concentration of 300g/concentration,
After preparing a homogeneous aqueous slurry of lead oxide, the aqueous slurry was heated to about 40°C and, with stirring, an ammonium nitrate solution prepared to a concentration of 10Mol/PbO was added (with a molar ratio of NO 3 - /PbO of 0.2 to 40°C). (Amount in the range of 2.0) Slowly add the mixture, and then further boil at 40℃ after addition.
Stirring was continued for 30 minutes to allow ammonium nitrate to become fully accustomed to lead oxide, and then heated to 80-90℃ to volatilize the ammonia contained, and the pH of this reaction solution was 7.5.
Heating continued until . This took 5 hours. Thereafter, the reaction solution was allowed to stand at room temperature, and the coarse crystals formed were filtered off. The lead compound obtained by the above treatment is coarse cubic basic lead nitrate (Pb(NO 3 ) (OH), Pb 3
(NO 3 ) (OH) 5 , etc.). Next, the obtained lead compound was dried at 130°C for 2 hours, and then dried at low temperature.
A sample was obtained. This drying changes the basicity of the lead compound, resulting in Pb 3 (NO 3 ) (OH) 5 , Pb 7 (NO 3 ) 4
It became basic lead nitrate such as (OH) 10 , but the rough cubic shape did not change. Furthermore, the samples obtained by low-temperature drying were fired at 450°C and 600°C for 2 hours, respectively, to obtain samples fired at 450°C and 600°C. This firing changed the lead compound into trioxide and lead monoxide, but the coarse cubic shape remained unchanged. In addition, where the content of the manufacturing conditions was changed in the above manufacturing conditions, the content shown in Table 1 was followed. Each physical property of the coarse particles produced here was measured by the following method. a Grain density Measured using a pycnometer in a conventional manner. b. Specific Volume (ml/g) The specific volume was measured by performing a drop impact for 20 minutes using a specific volume tester manufactured by Ishiyama Scientific Instruments Co., Ltd., which rotates 15 times per minute and performs a drop impact 30 times. c Number average particle size (μ) Observed using an optical microscope at a magnification of 40 times,
The size of the particles was measured, and the average particle diameter (μ) was determined from the number average of the size of each particle. d Crystal type Measured by powder measurement method using an X-ray self-recording diffractometer manufactured by Rigaku Denki Co., Ltd. In addition, the crystal forms were indicated using the following abbreviations. Lissage type - Lead oxide: L-PbO Mashkoto type - Lead oxide: M-PbO Trilead tetraoxide: Pb 3 O 4 Basic lead nitrate: BNL BNL stands for Pb (NO 3 ) (OH), Pb 3 (NO 3 )
(OH) 5 and Pb 7 (NO 3 ) 4 (OH) 10 were collectively named. e Angle of repose (degrees) Measured using a powder angle of repose measuring device manufactured by Takabayashi Rika Co., Ltd. f Degree of pulverization (%) Take 100 g of a granular sample into a plastic cylindrical container with an internal volume of 140 ml, fix it on a shaker that makes horizontal reciprocating motion (amplitude 40 mm, number of shakes 300 R.PM), and shake it for 10 minutes. It was collected and classified using a 150 mesh sieve, and the degree of pulverization was determined from the amount A (g) passing through the sieve. The above results are also shown in Table 1. As a comparative example, the wet and dry lead oxide used as the raw material in this example was subjected to rolling granulation extrusion granulation, spray drying granulation, and sintering at 600°C for 2 hours in an oxygen atmosphere. and granular lead oxide produced according to the method described in US Pat. No. 3,623,838, each physical property was measured in the same manner as in this example, and the results are also shown in Table 2. The rolling granulation of lead oxide was carried out by supplying each lead oxide to a rotating disk-type rolling granulator, and spraying water while rotating the tray. Extrusion granulation was carried out by adding 60 ml of water to 1 kg of each lead oxide, kneading the mixture to obtain a homogeneous wet state, and then extruding the mixture into a cylinder with a diameter of 2 mm using a meat grinder type granulator. Also, for spray drying granulation, add 400ml of water to 1kg of each lead oxide.
was added to make a homogeneous paste, and then dried under hot air at 250°C using a disc-type spray dryer. Furthermore, for granulation according to the method described in US Pat. No. 3,623,838, 60 ml of water was added to 1 kg of lead zinc oxide (so-called lead powder) prepared by the method described in Reference Example 2, and the mixture was kneaded to obtain a homogeneous product. After the mixture was brought into a moist state, it was extruded into a cylindrical shape with a diameter of 2 mm using a meat grinder type granulator. Each of the obtained granules was dried at 130°C for 2 hours if necessary, and then calcined at 550-600°C for 2 hours. Each of the obtained granular fired products is coarsely crushed if necessary.
Classify using a 150 mesh sieve and 246
Granular lead oxide between 104μ and 104μ was obtained (sample numbers H-1 to H-7)
【表】【table】
【表】
〓〓〓〓
[Table] 〓〓〓〓
【表】
以上の結果、各種の酸化鉛を原料として、その
水性スラリー中に硝酸アンモンをNO3 -/PbOの
モル割合で0.2乃至3.0の範囲内で加え、初期は50
℃以下の低温で充分良くPbOとNH4NO3とを慣ま
した後、アンモニアが挿散する条件下でアンモニ
ア分を揮散せしめ、塩基性の硝酸鉛(Pb
(NO3)・(OH)等)の粗大結晶を生成せしめ、そ
れを回収後、必要に応じて、洗浄、乾燥すると
Pb3(NO3)(OH)5やPb7(NO3)4(OH)10等の塩
基性硝酸鉛が生成し、さらに高温で焼成すると粗
大粒子の酸化鉛が生成回収することが良く理解さ
れる。
この粗大粒子の酸化鉛は、常法により製造され
た酸化鉛粒子の5倍以上、大きいものは20倍以上
の粒径を持つており、しかも安息角が小さく、流
れ性のある取り扱い容易な酸化鉛であり、しかも
従来の粒状の酸化鉛に較べて粒化度が小さく粉に
なり難く、人体に有害である鉛化合物の取り扱い
上有用であることが良く理解される。[Table] As a result, using various lead oxides as raw materials, ammonium nitrate was added to the aqueous slurry at a molar ratio of NO 3 - /PbO in the range of 0.2 to 3.0, and the initial concentration was 50
After thoroughly acclimatizing PbO and NH 4 NO 3 at a low temperature below ℃, the ammonia content is volatilized under conditions where ammonia is intercalated, and basic lead nitrate (Pb
Coarse crystals of (NO 3 ), (OH), etc.) are generated, and after collecting them, they are washed and dried as necessary.
It is well understood that basic lead nitrates such as Pb 3 (NO 3 ) (OH) 5 and Pb 7 (NO 3 ) 4 (OH) 10 are generated, and when fired at higher temperatures, coarse particles of lead oxide are generated and recovered. be done. These coarse particles of lead oxide have a particle size that is more than 5 times larger than lead oxide particles produced by conventional methods, and the larger ones are more than 20 times larger.In addition, they have a small angle of repose, making them easy to handle due to their flowability. It is well understood that it is lead and has a smaller granularity than conventional granular lead oxide and is less likely to turn into powder, making it useful in handling lead compounds that are harmful to the human body.
第1図は本発明による酸化鉛粒状物の光学顕微
鏡写真(倍率50倍)である。
〓〓〓〓
FIG. 1 is an optical micrograph (50x magnification) of lead oxide particles according to the present invention. 〓〓〓〓
Claims (1)
方晶粒子を焼成し、立方体の形状の一酸化鉛或い
は四三酸化鉛の粒子を形成させることを特徴とす
る酸化鉛粒状物の製造法。 2 一酸化鉛と一酸化鉛当り0.2乃至2.0モル倍の
硝酸アンモニウムとを、水性媒体中で且つ最終ス
ラリーのPHが4.0乃至10.0となる条件下に混合
し、このスラリーを放置して塩基性硝酸鉛の一辺
の長さが0.05mm以上の粗大立方晶粒子を成長さ
せ、次いでこの立方晶粒子を焼成し、立方体の形
状の一酸化鉛或いは四三酸化鉛の粒子を形成させ
ることを特徴とする酸化鉛粒状物の製造法。[Claims] 1. A method characterized by firing cubic particles of basic lead nitrate with a side length of 0.05 mm or more to form cubic particles of lead monoxide or trilead tetroxide. Method for producing lead oxide granules. 2. Mix lead monoxide and ammonium nitrate in an amount of 0.2 to 2.0 moles per lead monoxide in an aqueous medium under conditions such that the pH of the final slurry is 4.0 to 10.0, and leave this slurry to form basic lead nitrate. An oxidation process characterized by growing coarse cubic grains with a side length of 0.05 mm or more, and then firing the cubic grains to form cube-shaped lead monoxide or trilead tetroxide particles. Method of manufacturing lead granules.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP260780A JPS56100134A (en) | 1980-01-16 | 1980-01-16 | Manufacture of lead oxide granule |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP260780A JPS56100134A (en) | 1980-01-16 | 1980-01-16 | Manufacture of lead oxide granule |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS56100134A JPS56100134A (en) | 1981-08-11 |
JPS629526B2 true JPS629526B2 (en) | 1987-02-28 |
Family
ID=11534076
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP260780A Granted JPS56100134A (en) | 1980-01-16 | 1980-01-16 | Manufacture of lead oxide granule |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS56100134A (en) |
-
1980
- 1980-01-16 JP JP260780A patent/JPS56100134A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS56100134A (en) | 1981-08-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
KR100427005B1 (en) | Spheroidally Agglomerated Basic Cobalt(II) Carbonate and Spheroidally Agglomerated Cobalt(II) Hydroxide, Process for Their Production and Their Use | |
SA08290351B1 (en) | Catalyst for Producing of Acrylic Acid and Method for Producing Acrylic Acid Using the Catalyst | |
JP2003335519A (en) | Method for producing magnesium potassium titanate and lithium potassium titanate | |
JP2004243213A (en) | Catalyst for manufacture of acrylic acid and method for manufacturing acrylic acid | |
JPH0559845B2 (en) | ||
JPS629526B2 (en) | ||
JP5131098B2 (en) | Nickel fine powder and method for producing the same | |
US3623838A (en) | Process for the production of lead oxides | |
JP3690939B2 (en) | Catalyst for synthesizing methacrylic acid and method for producing methacrylic acid | |
JPH0323519B2 (en) | ||
JP4253176B2 (en) | Catalyst for producing acrylic acid and method for producing acrylic acid | |
JPH0138042B2 (en) | ||
JP3608147B2 (en) | Granular sulfuric acid bitter fertilizer and its production method | |
JP2003267730A (en) | METHOD FOR PRODUCING FeO POWDER | |
EP0434762B1 (en) | Nonpigmentary titanium dioxide powders | |
JPH0380118A (en) | Chromium spinel and its production | |
JPH11349319A (en) | Production of activated carbon | |
JPH0710731B2 (en) | Synthesis of lanthanum-alkaline earth metal-copper-oxygen superconducting materials | |
SU245032A1 (en) | Method for preparing catalyst for producing phthalic anhydride | |
JP2003277802A (en) | Rhodium powder | |
JPH02145431A (en) | Production of manganese oxide of large grain diameter | |
JP2023131778A (en) | Production method of dissimilar metal-doped cerium oxide | |
JPH02192408A (en) | Production of aluminum nitride powder | |
JP2023123327A (en) | Negative thermal expansion material and composite material | |
JP2004231483A (en) | Method for production of mullite whisker |