201211264 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種製造粒狀金屬之方法，其將黏聚物 (該黏聚物係將含有金屬氧化物與碳質還原劑之混合物作 為原料）供給至爐床上並進行加熱’將原料混合物中之金 屬氧化物還原熔融而製造粒狀金屬。 再者’於本說明書中，係將本發明之最有效地利用之 粒狀金屬鐵之製造方法作為主體進行說明，但本發明並不 限定於此，例如於對含鉻礦石或含鎳礦石等進行加熱、還 原而製造鉻鐵或鎳鐵等時亦可有效地利用。另外，於本發 明中所謂「粒狀」，並不表示必須為真球狀，而包括橢圓狀、 卵形狀、或其等稍微扁平化者等。 【先前技術】 作為由『將含有「鐵礦石或氧化鐵等含有氧化鐵之物 質」與「碳質還原劑」之混合物作為原料之黏聚物』獲得 粒狀金屬鐵之方法，現已開發出直接還原煉鐵法。於該煉 鐵法中，將上述黏聚物裝入至加熱爐之爐床上，於爐内利 用來自加熱燃燒器之氣體傳熱或輻射熱進行加熱，藉此利 用碳質還原劑使黏聚物中之氧化鐵還原，、繼而使所得之還 原鐵渗破n其次使其與副生之熔渣分離並凝聚成粒 狀後，使其冷卻凝固而獲得粒狀金屬鐵。 因上述煉鐵法不需要高爐等大規模設備，或不需要焦 碳等資源方面之適應性較高，故最近正盛行實用化研究。 但若要以1業規模實施，則包括操作穩定性或安全性、經 4 201211264 濟性、粒狀金屬鐵（製品）之品質、生產性等在内，必須 進:步改善之課題甚多。因此，本中請人先前於專利文獻1 中提出如下方法：於加熱還原含有碳質還原劑與氧化鐵之 成形體而製造金屬鐵時，將碳質還原劑之消耗量與加熱還 原所需之熱能抑制為必要最小限度，以實用性規模以更低 之成本高效率地達成氡化鐵之還原。於該文獻之實施例中 揭不有如下之例.對藉由摻合鐵礦石、碳材及黏合劑進行 k粒而製k之平均直徑為i 7 mm之顆粒進行加熱還原而製 造金屬鐵。 [專利文獻日本特開平11 —241111號公報 【發明内容】 根據上述專利文獻丨，考慮到氧化鐵之還原所需之化學 計量及C對所生成之金屬鐵之固溶量，而適當地控制碳質 還原劑之摻合量，進而考慮到c固溶所伴隨之金屬鐵之熔 點，而適當地控制加熱溫度，藉此，可高效率地進行由必 要最小限度之碳質還原劑之使用4、與由加熱溫度下氧化 鐵之加熱還原與熔融所致之熔渣的分離，可確立於工業規 模下更經濟且實用性高之金屬鐵之製造方法。但仍在課求 進一步增大每一有效爐床單位面積之單位時間内的粒狀金 屬鐵之生產量’提高粒狀金屬鐵之生產性。 本發明係著眼於如上所述之情況而完成者，其目的在 於提供如下之技術：於加熱含有金屬氧化物與碳質還原劑 之黏聚物，使黏聚物所含之金屬氧化物還原熔融而製造粒 狀金屬時’進一步提高粒狀金屬之生產性。 201211264 所謂可解決上述課題之本發明之粒狀金屬之製造方 法，係指「將含有金屬氧化物與碳質還原劑之黏聚物供給 至移動床型還原溶融爐之爐床上並進行加熱，將上述金屬 氧化物還原熔融後’將所得之粒狀金屬冷卻，之後排出至 上述爐外並回收」之粒狀金屬之製造方法；該方法具有如 下要旨：將上述爐床上之黏聚物之鋪設密度設為〇5以上進 行加熱時’將平均直徑為1 7.5 mm以上之黏聚物供給至上 述爐床上。 較佳為於上述爐床上預先鋪設碳質物質，以上述黏聚 物成為一層之方式供給至該碳質物質層上。 上述金屬氧化物’例如可使用氧化鐵或煉鐵粉塵。上 述移動床型還原熔融爐，例如可使用旋轉爐床爐。較佳為 於上述移動床型還原熔融爐之前半區域將爐内溫度控制為 1300〜1450 C，於後半區域則將爐内溫度控制為14〇〇〜 1550°C。另外，較佳為上述移動床型還原熔融爐之後半區 域之爐内溫度設定為高於前半區域之爐内溫度。 根據本發明，由於適當地控制供給至爐床上之黏聚物 之平均直徑、與於爐床上加熱黏聚物時之黏聚物之鋪設密 度’故而可提高粒狀金屬之生產性。 【實施方式】 本發明人為了提高「將含有金屬氧化物與碳質還原劑 之黏聚物供給至移動床型還原熔融爐之爐床上並進行加 熱，使黏聚物所含之金屬氧化物還原熔融而製造粒狀金屬 時」之生產性而反覆深入研究。其結果發現，若 6 201211264 (a)準備平均直徑為17 5mm以上者作為上述黏聚物， (b )將上述爐床上之黏聚物之鋪設密度設為〇 $以上 進行加熱，則可提高粒狀金屬之生產性，從而完成本發明。 完成本發明之過程如下。 上述專利文獻1中，於加熱還原含有碳質還原劑與氧 化鐵之成形體而製造金屬鐵時，使用平均直徑為17❿爪之 顆粒（黏聚物）作為成形體。之所以使用平均直徑為17 之黏聚物，係因為認為若黏聚物變大，則向爐内之爐床上 之黏聚物傳熱花費較長時間，反應時間變長，因此粒狀金 屬鐵之生產性惡化。 然而，本發明人對黏聚物之大小與生產性之關係進一 步進行了詳細研究，結果可知使用平均直徑為丨7 5 mm以 上之黏聚物可提高粒狀金屬之生產性之新事實。使用圖7 說明此事實。 圖7係後述實施例中所示之圖表，表示黏聚物之平均 直k與生產性心數之關係。於圖7中，所謂生產性指數， 係私將使用平均直徑為17.5 mm ( 1.75 cm)之黏聚物製造 粒狀金屬鐵時之生產性設為100時之相對值，該生產性係 每有效爐床單位面積之單位時間内的粒狀金屬鐵之生產 量（詳細情況於後文中加以敍述）。 由圖7可知，與使用平均直徑為16 〇 mm ( 1 6〇 cm) 之黏聚物時相比，使用平均直徑為17 5 mm以上之黏聚物 (具體而言，平均直徑為175〜32.〇mm)時之生產性指數 更大’粒狀金屬鐵之生產性更加提高。 7 201211264 並且，該圖7表示：根據各實驗結果，對使爐床上之 黏聚物彼此之距離r固疋時（即’使爐床上之黏聚物之鋪設 密度改變時）之關係進行再評價（模擬）之結果。此時， 所謂鋪設密度，係表示於每一有效爐床單位面積所鋪設之 黏聚物之填充密度，該密度可根據爐床上之黏聚物之投影 面積算出（詳細情況於後文中加以敍述）。圖7表示根據圖 5之結果進行再評價之結果’由該圖5所示之平均直徑與反 應時間之關係可知’由於實際之測定值分別僅存在少許偏 差’故而採用如下方法：進行利用曲線近似兩者之關係之 正規化，使用該曲線進行再評價》此方法係科學之解析方 法之一。 因於評價粒狀金屬之生產性時最重要之因素係反應時 間與良率（即’製品回收率），故特別根據實驗資料將該等 特性正規化並再評價。再者，黏聚物之視密度亦為對生產 性造成影響之重要因素，但例如對於直徑為16.〇 mm〜32.0 mm之範圍内之黏聚物，只要採用相同之黏聚化方法，則視 密度之偏差甚少，於綜合評價中，可預先評價為：即便看 作大致固定亦無問題。於圖7中，如後述實施例所示，隨 著黏聚物之平均直徑變大’黏聚物之鋪設密度亦變大（參 照下述表6 )。因此’由上述圖7亦可瞭解到，藉由除了適 當地控制黏聚物之平均直徑以外，亦適當地控制該鋪設密 度，可提高粒狀金屬鐵之生產性。即可知：根據本發明， 藉由同時控制黏聚物之鋪設密度與平均直徑，可提高粒狀 金屬鐵之生產性。 8 201211264 身 細說明。 mm以上者作為黏 ’對本發明之製造方法進行詳 於本發明中，準備平均直徑為1 7.5 聚物。 準備使含有金屬氧化物與碳質還原劑之混合物黏聚化 :成者作為上述黏聚物。金屬氧化物例如可使用含有氧化 鐵二礦石、含錄礦石等。特収作為含有氧化 吏用鐵礦石或鐵砂、煉鐵粉塵、非鐵冶煉殘渣、 鐵廢棄物等即可。作為碳質還原劑，使用含碳物質即可， 例如使用石碳或焦碳等即可。 於上述混合物中，亦可摻合黏合劑或含Mg〇物質、含 0物質等作為其他成分。黏合劑例如可使用多糖類（例 =小麥粉等殿粉等）等。含M g 〇物質例如可使用m g 〇粉末 =然礦石或自海水等中萃取之含Mg0物質、或碳酸鎮 gco3)等。含Ca〇㈣例如可使用生 石灰石（主要成分為cac03)等。 或 X上述黏聚物之平均直徑設為17 5 mm以上。通常上述 黏聚物之平均直徑較小者於爐内之傳熱所需之時間變短， 反應時間亦可縮短。但是，若減小黏聚物之平均直徑，則 變得難以於爐床上所鋪設之碳質物質之上均句地鋪滿，且 加=而獲得之粒狀金屬之粒徑或單位f量耗會變小。若 所得之粒狀金屬變小，則必須對其操作特別留意、，難以將 粒狀金屬供給至電爐或轉爐等精煉爐中。另外，就熔解特 性之觀點而言，粒狀金屬變小亦並非較佳。因卜二= 明中’將黏聚物之平均直徑設為17·5 mm以上。上述黏聚 201211264 物之平均直徑較佳m5_以上，更佳為195_以上， 進而較佳為20 _以上。黏聚物之平均直徑之上限並無特 別限疋，但由於若黏聚物之平均直徑超過Μ議，則爐内 之傳熱會過度花費時間，故而反應時間變長，生產性劣化。 另外，若欲增大黏聚物之平均直徑，則存在造粒效率變低 之傾向。因此，較佳為黏聚物之平均直徑設為31咖以下。 更佳為黏聚物之平均直徑為2 8 mm以下。 上述黏聚物之形狀並無特別限定，例如只要為顆粒 (pellet)狀或團塊（briquette)狀等即可。 _上述黏聚物之直徑係利用游標卡尺測定黏聚物之長 徑、與於垂直於該長徑之方向所測定之短徑，平均之而求 出[直徑=(長徑+短徑）/2]。黏聚物之大小係使用游標 卡尺對至少20個進行測定，將平均之所得者作為平均直 徑。再者，於黏聚物之平均直徑為a mm之情形時，較佳為 黏聚物之直徑（絕對值）分佈於α ±5 mm之範圍内。 於本發明中，將爐床上之黏聚物之鋪設密度設為〇 5以 上而加熱處理平均直徑為17.5 mm以上之黏聚物甚為重 要°先前認為，若增大黏聚物之平均直徑，則生產性會惡 化’但根據本發明，可瞭解到如下極為重要之事實··若於 爐床上之黏聚物之鋪設密度為〇.5以上之狀態下加熱平均 直徑為1 7· 5 mm以上之黏聚物，則如後述實施例所證實， 與先前之常識相反，生產性提高β但是，由於若黏聚物之 鋪設密度未達〇·5 ’則於每一有效爐床單位面積中所鋪設之 黏聚物之密度變得過小，故而即便將粒徑提高至1 7 5 mm 201211264 以上，總體而言粒狀金屬之生成量亦會變少，無法提高生 產性。因此’黏聚物之舖設密度設為〇 5以上。建議儘可能 增大該鋪設密度’較佳為〇 · 6以上。黏聚物之鋪設密度之上 限並無特別限定’但由於若以鋪設密度超過〇. 8之方式供給 黏聚物’則有時黏聚物會重疊成2層以上，而難以均勻地 加熱黏聚物，故而難以製造高品質之粒狀鐵。因此，黏聚 物之鋪設密度之上限較佳為設為0.8。黏聚物之鋪設密度更 佳為0.7以下。 此處，對黏聚物之鋪設密度進行詳細說明。黏聚物之 鋪設密度係根據於爐床上所鋪滿之黏聚物向爐床之投影面 積率而算出。使用圖丨說明鋪設密度之算出方法。 圖1係示意性地表示於爐床上所鋪滿之黏聚物之平面 圖。黏聚物向爐床之投影面積率可由下述式（1)算出。 投影面積率（％)=[爐床上之所有黏聚物之投影面積 /有效爐床面積]X100.，·（1) 將黏聚物假設為真球，將黏聚物之平均直徑設為Dp， 將黏聚物彼此之距離設& "夺，黏聚物向爐床之投^面積^ 可由下述式（2)算出。 投影面積率（％) =7rx(Dp) V4/{(Dp+r + r) χ30 5/ 2}χ1〇〇(〇/0)…（2) 將黏聚物彼此之距離r設為”，投影面積率取 值，最大投影面積率成.為固定之值（9〇69%)。將該 影面積率設為"夺，本發明中將「根據點聚物之平均亩： DP與黏聚物彼此之距離Γ由上述式（2 徑 叫ί又衫面積率 201211264 之相對值」定義為鋪設密度。 此處，為了更詳細地說明鋪設密度之實際情形，而將 於約61 cm見方之平板狀容器鋪滿平均直徑為18 2 黏聚物時之情況示於圖2。 圖2之Case, (a)係於容器内於每1 m2單位面積令填 充9_3 kg黏聚物之例，此時之鋪設密度為〇 4。可知：因將 鋪設密度設為0.4時之理論填充量為於每1 m2單位面積中 為9.33 kg ’故Case. ( a)所示之充填量與鋪設密度幾乎等 於理論值。 圖2之Case. ( b)係於容器内於每1 m2單位面積中填 充1 3.9 kg黏聚物之例’此時之鋪設密度為〇 6。可知：因 將鋪設密度設為0.6時之理論填充量為於每1 m2單位面積 中為14.0 kg，故Case, (b)所示之充填量與鋪設密度幾乎 等於理論值。 圖2之Case. ( c)係於容器内於每i m2單位面積中填 充18.5 kg黏聚物之例’此時之鋪設密度為〇.8。可知：因 將鋪設密度設為0.8時之理論填充量為於每1 m2單位面積 中為18.66 kg ’故Case, (c)所示之充填量與鋪設密度幾乎 等於理論值。 圖2之Case. ( d)係於容器内於每1 m2單位面積中填 充23 _2 kg黏聚物之例，此時之鋪設密度為1 ·〇。可知：因 將鋪設密度設為1.0時之理論填充量為於每1 m2單位面積 中為23.33 kg ’故Case. ( d)所示之充填量與鋪設密度幾乎 等於理論值。 12 201211264 並且’如圖2之Case, (d)所示，以鋪設密度成為i 〇 之方式將黏聚物鋪滿於實際之爐床上非常困難，事實上， 若於現場將鋪設密度成為丨.0之量之黏聚物供給至爐内，則 會產生所投入之黏聚物重疊等新問題。因此，為了以黏聚 物不重疊之方式供給至爐内，如圖2之Case(c)所示’，通 過各種實證實驗可判明鋪設密度之上限較佳為〇 8左右。 另外’如圖2之Case, (a)所示，可預想於鋪設密度為 〇·4之情形時，於爐床上會產生非常多之空隙，生產性顯著 降低。因此，認為鋪設密度之下限值應為成為圖2之case. (a)與Case. ( b)之中間值之〇.5左右。 繼而，將黏聚物彼此之距離r、與投影面積率或舖設密 度之關係示於圖3。於圖3中’籲表示投影面積率之結果， □表示鋪設密度之結果。㈣3可知，隨著黏聚物彼此之 距離r變大，黏聚物之投影面積率及黏聚物之鋪設密度均變 小。另外，根據黏聚物彼此之距離Γ，投影面積率與鋪設密 度之間可確認良好之相關關係。 繼而，將「於丨4.0〜32.0mm範圍内改變黏聚物之平均 直徑時之鋪設密度與黏聚物向爐内之供給量之關係」示於 圖4。再者，黏聚物之供給量表示每一有效爐床面積之供給 質量。 於圖4中，連接點（A)與點（B)之直線表示：使用 :均直徑為17.5 mm以上之黏聚物，將黏聚物之鋪設密度 6又為0.5時之黏聚物向爐内之供給量的範圍。連接點（c ) 與點（D)之直線表示：使用平均直徑為17.5随以上之黏 13 201211264 聚物，將黏聚物之鋪設密度設為0.8時之黏聚物向爐内之供 給量的範圍。由圖4可知’為了將爐床上之黏聚物之鋪設 密度控制為0.5以上’只要調整黏聚物之平均直徑與黏聚物 向爐内之供給量（每一有效爐床面積之供給質量）即可。 利用移動床型還原溶融爐加熱上述黏聚物，使黏聚物 中之金屬氧化物還原熔融而製造粒狀金屬。本發明中使用 之移動床型還原熔融爐或爐内之加熱條件並無特別限定， 可採用公知之條件。 上述移動床型還原熔融爐例如可使用旋轉爐床爐。移 動床型還原炼融爐之爐床寬度並無特別限定，根據本發 明’即便係爐床寬度為4 mm以上之實機，亦可以經濟上有 利之條件提高粒狀金屬之生產性。 較佳為於將上述黏聚物供給至爐床上之前，於爐床上 預先鋪設碳質物質（以下有時稱為鋪床材），以上述黏聚物 成為一層之方式供給至該碳質物質層上。鋪床材成為黏聚 物所含之碳不足時之碳供給源，同時發揮爐床保護材之作 用》 上述鋪床材之厚度並無特別限定，但較佳為設為3 mm 以上。即，因於使用實機作為上述移動床型還原熔融爐之 情形時，爐床寬度達數m，故存在難以遍及整個寬度方向均 勻地鋪設鋪床材，產生厚度為2〜8 mm左右之偏差之情況。 因此，為了不產生未被鋪床材覆蓋之爐床部分，鋪床材較 佳為以3 mm以上之厚度鋪設。鋪床材之厚度更佳為5 以上，進而較佳為10 mm以上。於本發明中，因特別增大 14 201211264 了黏聚物’故即便使鋪床材較厚，黏聚物亦難以埋於鋪床 材中，還原效率幾乎不降低。具體而纟，於使用平均直徑 為爪爪以上之黏聚物之情形時，較厚之鋪床材尤其有效。 再者’對上述鋪床材之厚度之上限亦無特別限定，但由於 若鋪床材之厚度超過30 mm，則於本發明中黏聚物亦會藏 入舖床材中，故而存在阻礙對黏聚物供給熱、還原效率降 低之情況。其結果’易導致粒狀金屬變形，或内部品質劣 化。因此，鋪床材之厚度較佳為設為3〇 mm以 2。-以下，進而較佳為15mm以下。 用作上述鋪床材之碳質物質，可使用作為上述碳質還 原劑所例示者。碳質物質例如建議使用粒子直徑為3 〇職 以下者。若碳質物質之粒子直徑超過3 〇随，則有溶融之 熔渣μ落至奴質物質之空隙間而到達床表面，侵蝕爐床之 虞。石反質物質之粒子直徑更佳為2 〇 mm以下。但是，由於 右碳質物質之粒子直徑低於G 5 m m之碳質物質之比率變得 過大則黏聚物會藏入鋪床材之中，加熱效率變低，粒狀 金屬之生產性降低，故而並非較佳。 、供給至鋪設有鋪床材之爐床上之上述黏聚物較佳為以 成為1層之方式供給黏聚物。為了增大粒狀金屬鐵之生產 量，通常情況下考慮增加供給至爐内之黏聚物量，若增加 聚物之供'給4 ’則«物於爐#上會積層| 2層或3 層以上。於此情形時，上方之黏聚物自爐體受到充分之熱 而還原熔融’但未對下方之黏聚物充分地供給熱，因此易 殘留未還原部分。若僅上方之黏聚物還原熔融’熔融鐵與 15 201211264 下方之未料還原鐵等-體化，Mlj無法回收高品質之粒狀 金屬鐵。因此，建議如本發明般，於在爐内確實地進行固 體還原與滲碳溶融之情形時，以爐床上之黏聚物大致成為i 層之方式供給黏聚物。 為了使爐床上之黏聚物成為1層，而於供給至爐内之 黏聚物進人加熱反應區域之前，以遍及有效爐床之寬度整 體均勻鋪滿黏聚物之方4，例如若使用顆粒調平器，則可 調整爐床上之黏聚物之鋪設。 利用移動床型還原熔融爐加熱上述黏聚物，使黏聚物 所3之金屬氧化物還原溶融時之加熱條件，可採用常規方 法之條件即，供給上述黏聚物至爐床上，於特^溫度進 行固體還原’進一步加熱保持直至熔解，肖此製造由雜質 所構成之炼渣（氧化物）與粒狀金㈣。對於爐床上之黏 聚物藉由议置於爐之上部（例如頂部）或側壁之數個燃 燒器之燃燒火焰之熱、或來自加熱至高溫之爐内财火物之 輻射熱進行加# ’自黏聚物之外周部向内部傳熱，進行固 體還原反應。 於爐之刖半區域’黏聚物一面維持固體狀態一面進巧 還原反應’於爐之後半區域，固體還原已結束之黏聚物内 之微小還原鐵一面 聚，與黏聚物内之 金屬鐵。 經由滲碳反應而於熔解之過程中相互凝 雜質（熔渣成分）分離’ 一面形成粒狀 由於爐之刖半區域係使黏聚物中之氧化鐵固體還原， 故而較佳為將爐内溫度控制A 1300〜145CTC左右。由於爐 16 201211264 原鐵滲碳、熔融，而使其凝 制為1400〜1550°C左右。再 之後半區域係使黏聚物中之還 聚’故而較佳為將爐内溫度控 者，於將爐内加熱i 1550°c以上之情形時，對黏聚物供給 過剩之熱，超過向黏聚物内傳熱之速度，、結果於固體還原 結束之前，部分成為熔融狀態’伴隨急遽之反應，結果引 起產生異常之造渣之熔融還原反應。 爐之後半區域之爐内溫度亦可設定為高於爐之前半區 域之爐内溫度。 於本發明中，如下述式（3 )所示，根據單位時間（小 時）之母有效爐床單位面積（m2)之粒狀金屬之生產量 (ton)而評價加熱上述黏聚物使金屬氧化物還原熔融而製 造粒狀金屬時之生產性。 生產性（ton/ m2/小時）=粒狀金屬之生產量（粒狀 金屬t〇n//小時）/有效爐床面積（m2)…（3) 於上述式（3)中’粒狀金屬之生產量（粒狀金屬ton /小時）以下述式（4 )表示。 粒狀金屬之生產量（粒狀金屬ton/小時）=黏聚物之 裝入I (黏聚物ton/小時）X由每1噸黏聚物所製造之粒 狀金屬之質量（粒狀金屬ton/黏聚物ton ) X製品回收率… (4) 於上述式（4)中，製品回收率係以「直徑為3 35 mm 以上之粒狀金屬鐵相對於所得之粒狀金屬之總量之比例[直 徑為3.35 mm以上之粒狀金屬鐵之質量/粒狀金屬鐵之總 量χ1〇〇]」算出。 17 201211264 再者，於下述實施例之實驗例2、3中，為了定量地評 價本發明之效果’故將平均直徑為17.5 mm之供試材（黏 聚物）設為標準黏聚物，以相對值（生產性指數）表示將 該標準黏聚物之生產性設為1 .〇〇時之各黏聚物之生產性。 以下，列舉實施例更具體地說明本發明，但本發明並 不受下述實施例限定，當然亦可於可適於前述後述宗旨之 範圍内適當地加入變更而實施，該等均包含於本發明之技 術範圍内。 [實施例] [實驗例1] 製作將含有金屬氧化物與碳質還原劑之混合物作為^ 料之黏聚物’將该黏聚物供給至移動床型還原熔融爐之切 床上並進行加熱，將原料混合物中之金屬氧化物還原熔罱 而製造粒狀金屬鐵。 即，使用下述表】你_ _ 所不之成分組成之鐵礦石作為金肩 氧化物，使用下述表2 κ _ 所不之成分組成之石碳作為碳質这 原劑來製造黏聚物。詳 Λ Α 〒、，、田而s ’於上述鐵礦石及上述石碎 之混合物中，摻合小來 私作為黏合劑’摻合石灰石或白雲 石專作為副原料來製作 蜻釭、⑽^ 十构直徑不同之顆粒狀黏聚物（供 δ式材h將供試材之摻厶 表3…卜，利用游標；： 值之百分率）示於下过 4。供試材之平均直徑係測 平均直徑，將結果示於下供試材之長徑與短徑，算 2 0個時之平均值。 於下述表4中’亦 _ 表示了各供試材之單位質量與視 18 201211264 測定20個之質量之結果之平均 由於液體（水銀）中浸潰黏聚物 度。供試材之單位質量係 值。供試材之視密度係藉 並測定其浮力而求出之值 利用實驗室規模之小型加熱爐（爐内之溫度為145〇。〔 分別加熱所得之平均直徑不同之供試材，調查使供試材所 含之鐵礦石還原熔融所需之時間（反應時間將反應時間 之測定結果示於下述表4。 將供試材之平均直棱（Dp )與反應時間之關係示於圖 5。圖5中以虛線所示之曲線表示繪圖點之近似曲線，以基 於供試材之平均直徑之2次式表示。由圖5可知，供試材 之平均直徑越大’反應時間就越長。 根據上述實驗例1之結果，使反應時間或製品回收率 正規化（Normalization)，綜合評價改變供試材彼此之距離 (下述實驗例2 )或供試材之鋪設密度（下述實驗例3 )時 之生產性。 [表1] — 鐵礦石 成分組成（晳晉％)-- 總Fe量 FeO Si02 CaO AI2O3 MgO MnO T1O2 P s 67.73 29.40 4.54 0.42 0.21 0.47 0.34 0.07 0.018 0.002 [表2] 石碳 成分組成p ί 量0/〇) 固定碳 揮發分 灰分 總計 77.21 16.65 6.14 100 201211264 [表3] 供試材 __#合組成（質量％) 鐵礦石 石碳 黏合劑 副原料 71.95 17.01 0.90 11.55 [表4]201211264 VI. Description of the Invention: [Technical Field] The present invention relates to a method for producing a granular metal which comprises a binder (the binder which contains a mixture of a metal oxide and a carbonaceous reducing agent as a raw material) The steel metal is supplied to the hearth and heated to reduce and melt the metal oxide in the raw material mixture to produce a granular metal. In the present specification, the method for producing the granular metal iron which is most effectively used in the present invention will be mainly described. However, the present invention is not limited thereto, and for example, a chromium-containing ore or a nickel-containing ore is used. It can also be effectively utilized when heating and reducing to produce ferrochrome or ferronickel. Further, the term "granular" as used in the present invention does not mean that it must be a true spherical shape, but includes an elliptical shape, an egg shape, or a slightly flattened person or the like. [Prior Art] A method for obtaining granular metallic iron by using a "mixture containing "iron oxide or iron oxide-containing material such as iron ore" and "carbonaceous reducing agent" as a raw material has been developed. Direct reduction ironmaking method. In the iron making method, the above-mentioned slime is charged into a hearth of a heating furnace, and is heated in the furnace by gas heat transfer or radiant heat from a heating burner, thereby using a carbonaceous reducing agent to make the binder The iron oxide is reduced, and then the obtained reduced iron is oozing n. Next, it is separated from the by-product slag and aggregated into a granular shape, and then cooled and solidified to obtain granular metallic iron. Since the above-described ironmaking method does not require large-scale equipment such as a blast furnace, or does not require high compatibility with resources such as coke, it has recently been popularized. However, if it is to be implemented on a scale of 1 industry, it will include many factors such as operational stability or safety, quality of 201211264, quality of granular metal iron (products), and productivity. Therefore, the present inventor has previously proposed a method of producing a metal iron by heating and reducing a molded body containing a carbonaceous reducing agent and iron oxide, and reducing the consumption of the carbonaceous reducing agent with heating and reduction. Thermal energy suppression is a necessary minimum, and the reduction of antimony iron is efficiently achieved at a lower cost on a practical scale. The following examples are given in the examples of the literature. The metal iron is prepared by heating and reducing particles having an average diameter of i 7 mm by k-doping iron ore, carbon material and binder. . [Patent Document] Japanese Laid-Open Patent Publication No. Hei 11-241111--A SUMMARY OF THE INVENTION According to the above-mentioned patent document, carbon is appropriately controlled in consideration of the stoichiometry required for reduction of iron oxide and the amount of solid solution of metal iron generated by C. The amount of the reducing agent to be blended, and in consideration of the melting point of the metallic iron accompanying c solid solution, the heating temperature is appropriately controlled, whereby the use of the minimum necessary carbonaceous reducing agent can be efficiently performed. Separation from slag due to heating reduction and melting by iron oxide at a heating temperature can establish a method for producing metal iron which is more economical and practical in industrial scale. However, it is still being sought to further increase the production amount of granular metal iron per unit time per unit area of each effective hearth' to increase the productivity of granular metal iron. The present invention has been made in view of the above circumstances, and an object thereof is to provide a technique for heating and melting a metal oxide containing a metal oxide and a carbonaceous reducing agent to reduce a metal oxide contained in the binder. When manufacturing granular metal, 'further increase the productivity of granular metal. 201211264 The method for producing a granular metal of the present invention which solves the above-mentioned problems means that "the binder containing a metal oxide and a carbonaceous reducing agent is supplied to a hearth of a moving bed type reductive melting furnace and heated. a method for producing a granular metal in which the metal oxide is reduced and melted, and then the obtained granular metal is cooled and then discharged to the outside of the furnace and recovered; the method has the following tenet: laying density of the above-mentioned grit on the hearth When it is set to 〇5 or more for heating, a binder having an average diameter of 1 7.5 mm or more is supplied to the above-mentioned hearth. Preferably, the carbonaceous material is preliminarily laid on the hearth, and the carbonaceous material layer is supplied as a layer of the above-mentioned adsorbent. As the above metal oxide, for example, iron oxide or iron-making dust can be used. In the above moving bed type reduction melting furnace, for example, a rotary hearth furnace can be used. Preferably, the furnace temperature is controlled to 1300 to 1450 C in the first half of the moving bed type reduction melting furnace, and the furnace temperature is controlled to 14 〇〇 to 1550 ° C in the second half. Further, it is preferable that the furnace temperature in the latter half of the moving bed type reduction melting furnace is set higher than the furnace temperature in the first half region. According to the present invention, the productivity of the granular metal can be improved by appropriately controlling the average diameter of the binder supplied to the hearth and the packing density of the binder when the binder is heated on the hearth. [Embodiment] The present inventors have attempted to improve the supply of a metal oxide containing a metal oxide and a carbonaceous reducing agent to a hearth of a moving bed type reduction melting furnace and heating it to reduce the metal oxide contained in the binder. The productivity of "melting to produce granular metal" has been studied in depth. As a result, it was found that 6 201211264 (a) when the average diameter is 17 5 mm or more is prepared as the above-mentioned binder, and (b) when the density of the binder of the above-mentioned hearth is set to 〇$ or more, heating can be performed. The productivity of the metal is thus completed to complete the present invention. The process of completing the present invention is as follows. In the above-mentioned Patent Document 1, when a metal body having a carbonaceous reducing agent and iron oxide is heated and reduced to produce metallic iron, particles (viscosity) having an average diameter of 17 jaws are used as a molded body. The reason why the use of an average particle diameter of 17 is because it is considered that if the binder becomes large, it takes a long time to transfer heat to the binder on the hearth in the furnace, and the reaction time becomes long, so the granular metal iron The productivity is deteriorating. However, the present inventors conducted further detailed studies on the relationship between the size and productivity of the binder, and as a result, it has been found that the use of a binder having an average diameter of 丨75 mm or more can improve the productivity of the granular metal. Use Figure 7 to illustrate this fact. Fig. 7 is a graph shown in the later-described embodiment, showing the relationship between the average straight k of the cohesive polymer and the number of productive hearts. In Fig. 7, the productivity index is the relative value when the productivity is set to 100 when the granular metal iron is produced by using an average diameter of 17.5 mm (1.75 cm). The production amount of granular metal iron per unit time per unit area of the hearth (details are described later). As can be seen from Fig. 7, the use of agglomerates having an average diameter of 17 5 mm or more is used as compared with the case of using an aggregate having an average diameter of 16 mm (16 cm) (specifically, an average diameter of 175 to 32) .〇mm) The productivity index is larger'. The productivity of granular metal iron is further improved. 7 201211264 Moreover, this FIG. 7 shows that, based on the results of the respective experiments, the relationship between the viscosity of the clay on the hearth is fixed (ie, when the density of the adhesive on the hearth is changed) is re-evaluated. The result of (simulation). In this case, the so-called packing density is the packing density of the adhesive which is laid per unit area of each effective hearth, and the density can be calculated from the projected area of the binder on the hearth (details will be described later) . Fig. 7 shows the result of re-evaluation based on the result of Fig. 5. From the relationship between the average diameter and the reaction time shown in Fig. 5, it is known that "there is only a slight deviation in the actual measured values," so the following method is employed: The normalization of the relationship between the two, using the curve for re-evaluation, this method is one of the analytical methods of science. Since the most important factors for evaluating the productivity of the granular metal are reaction time and yield (i.e., 'product recovery rate), these characteristics are normalized and re-evaluated based on experimental data. Furthermore, the apparent density of the binder is also an important factor affecting the productivity, but for example, for the binder in the range of 16. 〇 mm to 32.0 mm, as long as the same cohesive method is used, The deviation of the apparent density is very small, and in the comprehensive evaluation, it can be pre-evaluated as follows: even if it is considered to be substantially fixed, there is no problem. In Fig. 7, as shown in the later-described embodiment, as the average diameter of the binder becomes larger, the packing density of the binder becomes larger (refer to Table 6 below). Therefore, it can be understood from the above Fig. 7 that the productivity of the granular metallic iron can be improved by appropriately controlling the laying density in addition to the proper control of the average diameter of the binder. That is, according to the present invention, the productivity of the granular metallic iron can be improved by simultaneously controlling the laying density and the average diameter of the binder. 8 201211264 Detailed description. More than mm is used as the adhesive method. In the present invention, the average diameter is 1 7.5. It is prepared to cohere a mixture containing a metal oxide and a carbonaceous reducing agent: as the above-mentioned binder. As the metal oxide, for example, iron oxide-containing ore, ore-bearing or the like can be used. It can be used as iron ore, iron sand, iron-making dust, non-iron smelting residue, iron waste, etc. containing cerium oxide. As the carbonaceous reducing agent, a carbonaceous material may be used, and for example, stone carbon or coke may be used. In the above mixture, a binder or a substance containing Mg, a substance containing 0, or the like may be blended as other components. As the binder, for example, a polysaccharide (for example, a meal such as wheat flour) or the like can be used. The substance containing Mg may be, for example, m g 〇 powder = ore or Mg0-containing material extracted from seawater or the like, or carbonic acid gco3). As the Ca(R) containing material, for example, a limestone (the main component is cac03) or the like can be used. Or X The average diameter of the above-mentioned binder is set to 17 5 mm or more. Usually, the smaller the average diameter of the above-mentioned binder, the shorter the time required for heat transfer in the furnace, and the shorter the reaction time. However, if the average diameter of the cohesive polymer is reduced, it becomes difficult to uniformly spread the carbonaceous material laid on the hearth, and the particle size or unit f of the granular metal obtained by adding = It will become smaller. If the obtained granular metal is small, it is necessary to pay special attention to the operation thereof, and it is difficult to supply the granular metal to a refining furnace such as an electric furnace or a converter. Further, from the viewpoint of the melting characteristics, it is not preferable that the granular metal becomes small. In Bu II = Mingzhong' has an average diameter of the binder of 17·5 mm or more. The average diameter of the above-mentioned cohesive 201211264 is preferably m5_ or more, more preferably 195_ or more, still more preferably 20 _ or more. The upper limit of the average diameter of the binder is not particularly limited. However, if the average diameter of the binder exceeds the above, the heat transfer in the furnace is excessively time-consuming, so that the reaction time becomes long and the productivity is deteriorated. Further, if the average diameter of the binder is to be increased, the granulation efficiency tends to be low. Therefore, it is preferred that the average diameter of the binder is set to 31 coffee or less. More preferably, the average diameter of the binder is less than 28 mm. The shape of the above-mentioned binder is not particularly limited, and may be, for example, a pellet shape or a briquettte shape. _ The diameter of the above-mentioned viscous polymer is determined by measuring the long diameter of the viscous mass and the short diameter measured in the direction perpendicular to the long diameter by a vernier caliper, and obtaining the average [diameter = (long diameter + short diameter) / 2 ]. The size of the cohesive mass was measured using at least 20 vernier calipers, and the average was obtained as the average diameter. Further, in the case where the average diameter of the binder is a mm, it is preferred that the diameter (absolute value) of the binder is distributed within a range of α ± 5 mm. In the present invention, it is important to set the density of the binder of the binder on the hearth to be 〇5 or more and heat-treat the aggregate having an average diameter of 17.5 mm or more. It is considered that if the average diameter of the binder is increased, Then, the productivity is deteriorated. However, according to the present invention, it is understood that the following extremely important facts are obtained: If the packing density of the binder in the hearth is 〇.5 or more, the heating average diameter is 17.5 mm or more. The cohesive polymer is confirmed by the following examples. In contrast to the conventional knowledge, the productivity is improved by β. However, if the packing density of the binder is less than 〇·5', it is in the area per effective hearth. Since the density of the laid-up adhesive is too small, even if the particle size is increased to 175 mm or more in 201211264, the amount of particulate metal produced is generally small, and productivity cannot be improved. Therefore, the packing density of the binder is set to 〇 5 or more. It is recommended to increase the laying density as much as possible, preferably 〇 · 6 or more. The upper limit of the packing density of the binder is not particularly limited. However, if the binder is supplied in a manner that the packing density exceeds 〇8, the binder may overlap to form two or more layers, and it is difficult to uniformly heat the cohesive layer. It is difficult to manufacture high quality granular iron. Therefore, the upper limit of the packing density of the cohesive is preferably set to 0.8. The packing density of the binder is preferably 0.7 or less. Here, the packing density of the binder is described in detail. The packing density of the binder is calculated based on the projected area ratio of the binder which is spread on the hearth to the hearth. Use the diagram to explain how to calculate the packing density. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view schematically showing a cohesive polymer which is spread on a hearth. The projected area ratio of the binder to the hearth can be calculated by the following formula (1). Projection area ratio (%) = [projected area of all the cohesive mass on the hearth / effective hearth area] X100., (1) The viscosity is assumed to be a true ball, and the average diameter of the cohesive polymer is set to Dp. , the distance between the binders is set to &", and the area of the binder to the hearth ^ can be calculated by the following formula (2). Projection area ratio (%) = 7rx(Dp) V4/{(Dp+r + r) χ30 5/ 2}χ1〇〇(〇/0)...(2) Set the distance r between the binders to ", The projected area ratio is taken as the value, and the maximum projected area ratio is fixed. (9〇69%). The image area ratio is set to ", in the present invention, "based on the average acre of the point polymer: DP and sticky The distance between the polymers is defined by the above formula (2: the relative value of the diameter of the shirt and the area ratio of 201211264) as the laying density. Here, in order to explain the actual situation of the laying density in more detail, it will be about 61 cm square. The condition of the flat container covered with an average diameter of 18 2 is shown in Figure 2. Case of Figure 2, (a) is an example of filling 9_3 kg of polypolymer per 1 m2 unit area in a container. The laying density is 〇4. It can be seen that the theoretical filling amount when the laying density is 0.4 is 9.33 kg per 1 m2 unit area. Therefore, the filling amount and the laying density shown in Case. (a) are almost equal to Theoretical value. Figure 2, Case. (b) is an example of filling 1 3.9 kg of polymethane per 1 m2 of unit area in a container. The laying density at this time is 〇6. It is known that: The theoretical filling amount when the laying density is set to 0.6 is 14.0 kg per 1 m2 unit area, so the filling amount and the laying density shown by Case, (b) are almost equal to the theoretical value. Figure 2, Case. (c) In the container, 18.5 kg of the polyglocide is filled per unit area of i m2. The laying density at this time is 〇.8. It can be seen that the theoretical filling amount is set at every 1 m2 unit because the laying density is set to 0.8. The area is 18.66 kg 'cause Case, the filling and packing density shown in (c) is almost equal to the theoretical value. Figure 2, Case. (d) is filled in the container with 23 _2 kg per 1 m2 unit area. In the case of the material, the laying density at this time is 1 · 〇. It can be seen that the theoretical filling amount when the laying density is 1.0 is 23.33 kg per 1 m 2 unit area, so the filling shown in Case. (d) The amount and laying density are almost equal to the theoretical value. 12 201211264 And as shown in Case 2, (d), it is very difficult to spread the adhesive on the actual hearth in such a way that the laying density becomes i ,, in fact, If a bulk polymer having a density of 丨.0 is supplied to the furnace at the site, it will be produced. New problems such as the overlap of the binder. Therefore, in order to supply the binder to the furnace without overlapping, as shown in Case(c) of Fig. 2, it is found through various empirical experiments that the upper limit of the packing density is preferably 〇8 or so. In addition, as shown in Case 2 of Figure 2, (a), it is expected that when the packing density is 〇·4, a large number of voids are generated on the hearth, and productivity is remarkably lowered. Therefore, it is considered that the lower limit of the laying density should be about 5.5 which is the case of Figure 2. (a) and Case. (b). Next, the relationship between the distance r of the binders from each other, the projected area ratio, or the laying density is shown in Fig. 3. In Fig. 3, the result of the projected area ratio, □ indicates the result of the laying density. (4) 3 It can be seen that as the distance r between the binders becomes larger, the projected area ratio of the binder and the laying density of the binder become smaller. Further, according to the distance 黏 between the binders, a good correlation can be confirmed between the projected area ratio and the laid density. Next, the relationship between the laying density when the average diameter of the binder is changed in the range of 4.0 to 32.0 mm and the amount of the binder supplied to the furnace is shown in Fig. 4. Further, the supply amount of the binder indicates the supply quality of each effective hearth area. In Fig. 4, the straight line connecting the point (A) and the point (B) means: using: a cohesive polymer having a diameter of 17.5 mm or more, and a polycondensate having a density of 6 and a viscosity of 0.5 to the furnace The range of supply within. The straight line connecting the point (c) and the point (D) means: using the average diameter of 17.5 with the above-mentioned viscosity 13 201211264 polymer, the viscosity of the adhesive is set to 0.8 when the viscosity of the adhesive is set to 0.8. range. It can be seen from Fig. 4 that in order to control the packing density of the binder on the hearth to be 0.5 or more, it is only necessary to adjust the average diameter of the binder and the supply amount of the binder to the furnace (the supply quality of each effective hearth area). Just fine. The above-mentioned binder is heated by a moving bed type reduction melting furnace to reduce and melt the metal oxide in the binder to produce a granular metal. The heating conditions in the moving bed type reduction melting furnace or furnace used in the present invention are not particularly limited, and known conditions can be employed. For the above moving bed type reduction melting furnace, for example, a rotary hearth furnace can be used. The width of the hearth of the moving bed type reduction refining furnace is not particularly limited. According to the present invention, even if the furnace bed has a width of 4 mm or more, the productivity of the granular metal can be improved economically. Preferably, before the above-mentioned binder is supplied to the hearth, a carbonaceous substance (hereinafter sometimes referred to as a bed material) is preliminarily laid on the hearth, and the above-mentioned binder is supplied as a layer to the carbonaceous material layer. . The bed material is a carbon supply source when the carbon contained in the cohesive material is insufficient, and the bed material is used as a protective material. The thickness of the bed material is not particularly limited, but is preferably 3 mm or more. In other words, when the actual machine is used as the moving bed type reduction melting furnace, the width of the hearth is several m, so that it is difficult to uniformly lay the bed material over the entire width direction, and the thickness is about 2 to 8 mm. Happening. Therefore, in order not to produce a portion of the hearth that is not covered with the bed material, the bed material is preferably laid at a thickness of 3 mm or more. The thickness of the bed material is more preferably 5 or more, and further preferably 10 mm or more. In the present invention, since the binder is particularly increased by the fact that the binder is thick, the binder is hardly buried in the bed, and the reduction efficiency is hardly lowered. Specifically, thicker bedding materials are particularly effective when using an adhesive having an average diameter of more than a paw. Further, the upper limit of the thickness of the above-mentioned bed material is not particularly limited, but since the thickness of the bed material exceeds 30 mm, the binder is also hidden in the bed material in the present invention, so that there is a hindrance to the binder. Supply heat and reduction efficiency are reduced. As a result, the granular metal is easily deformed or the internal quality is deteriorated. Therefore, the thickness of the bed material is preferably set to 3 〇 mm to 2. - Hereinafter, it is more preferably 15 mm or less. As the carbonaceous material used as the above-mentioned bed-making material, those exemplified as the above-mentioned carbonaceous reductant can be used. For carbonaceous materials, for example, it is recommended to use a particle diameter of 3 or less. If the particle diameter of the carbonaceous material exceeds 3 〇, the molten slag μ falls between the voids of the nucleus material and reaches the surface of the bed, eroding the enthalpy of the hearth. The particle diameter of the stone anti-matter material is preferably 2 〇 mm or less. However, since the ratio of the carbonaceous material having a particle diameter of less than G 5 mm of the right carbonaceous substance becomes too large, the binder is hidden in the bed material, the heating efficiency is lowered, and the productivity of the granular metal is lowered, so that the productivity of the granular metal is lowered. Not preferred. Preferably, the above-mentioned binder which is supplied to the hearth on which the bed material is placed is supplied to the binder in a layer. In order to increase the production of granular metallic iron, it is usually considered to increase the amount of the cohesive polymer supplied to the furnace. If the addition of the polymer is given to '4', then the material will accumulate on the furnace # | 2 or more layers . In this case, the upper binder is subjected to sufficient heat from the furnace body to be reduced and melted, but the underlying binder is not sufficiently supplied with heat, so that the unreduced portion is likely to remain. If only the upper mucopolymer is reduced and melted, the molten iron and the unreacted reduced iron under 15 201211264 are oxidized, Mlj cannot recover high-quality granular metallic iron. Therefore, it is proposed to supply the binder in such a manner that the binder on the hearth is substantially i-layer in the case where the solid reduction and the carburization are reliably performed in the furnace as in the present invention. In order to make the cohesive polymer on the hearth into one layer, before the cohesive polymer supplied into the furnace enters the heating reaction zone, the cohesive polymer 4 is evenly spread over the entire width of the effective hearth, for example, if used. The particle leveler adjusts the laying of the binder on the hearth. The heating condition of the above-mentioned polycondensate in the moving bed type reduction melting furnace to reduce and melt the metal oxide of the polycondensate 3 can be supplied to the hearth by using the conditions of the conventional method. The temperature is subjected to solid reduction 'further heating until it is melted, and a slag (oxide) composed of impurities and granular gold (four) are produced. For the cohesive polymer on the hearth, the heat of combustion of several burners placed on the upper part of the furnace (for example, the top) or the side wall, or the radiant heat from the fireworks in the furnace heated to high temperature is added. The outer portion of the cohesive polymer transfers heat to the inside to carry out a solid reduction reaction. In the middle half of the furnace, the one side of the furnace maintains a solid state while undergoing a reduction reaction. In the latter half of the furnace, the micro-reduced iron in the end of the solid reduction is aggregated, and the metal iron in the binder . By separating the condensed impurities (slag component) during the melting process by the carburizing reaction, the surface is formed into a granular shape. Since the bismuth half of the furnace reduces the iron oxide solid in the viscous polymer, it is preferred to set the temperature inside the furnace. Control A 1300~145CTC or so. Because the furnace 16 201211264 is cast iron and melted, it is condensed to about 1400~1550 °C. In the latter half of the zone, the polycondensation in the binder is made. Therefore, it is preferred to control the temperature in the furnace. When the furnace is heated to a temperature of 1550 ° C or more, excess heat is supplied to the binder, and the excess is exceeded. The rate of heat transfer in the binder is such that, before the completion of the reduction of the solid, a part of the molten state is accompanied by an imminent reaction, and as a result, a smelting reduction reaction which causes abnormal slag formation is caused. The furnace temperature in the latter half of the furnace can also be set to be higher than the furnace temperature in the first half of the furnace. In the present invention, as shown in the following formula (3), the above-mentioned binder is heated to oxidize the metal according to the production amount (ton) of the granular metal per unit area (m2) of the mother effective hearth per unit time (hour). Productivity when the material is reduced and melted to produce a granular metal. Productivity (ton / m2 / hour) = production of granular metal (granular metal t〇n / / hour) / effective hearth area (m2) ... (3) in the above formula (3) 'granular metal The production amount (granular metal ton / hour) is represented by the following formula (4). Production of granular metal (granular metal ton / hour) = loading of the viscous polymer I (viscosity ton / hour) X The mass of the granular metal produced per ton of the viscous polymer (granular metal) Ton / cohesive ton ) X product recovery rate (4) In the above formula (4), the product recovery rate is "the total amount of granular metal iron with a diameter of 3 35 mm or more relative to the obtained granular metal" The ratio [mass of granular metallic iron having a diameter of 3.35 mm or more / total amount of granular metallic iron χ1〇〇] is calculated. 17 201211264 Further, in Experimental Examples 2 and 3 of the following examples, in order to quantitatively evaluate the effect of the present invention, a test material (viscose) having an average diameter of 17.5 mm was set as a standard binder. The productivity of each of the cohesive polymers when the productivity of the standard cohesive polymer was set to 1. The relative value (productivity index) was expressed. In the following, the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples, and may be appropriately modified and implemented within the scope of the above-described embodiments, which are included in the present invention. Within the technical scope of the invention. [Examples] [Experimental Example 1] A binder which contains a mixture of a metal oxide and a carbonaceous reducing agent as a material was prepared, and the binder was supplied to a bed of a moving bed type reduction melting furnace and heated. The metal oxide in the raw material mixture is reduced and melted to produce granular metallic iron. That is, use the iron ore composed of the components of the following table as the gold shoulder as the gold shoulder, and use the carbon of the composition of the following Table 2 κ _ as the carbon source to make the cohesive Things. Λ 〒 ,, 、, 田田 s 'In the above iron ore and the above-mentioned mixture of stone shreds, blending Xiaolai private as a binder' blending limestone or dolomite as an auxiliary material to make 蜻釭, (10)^ Granular clays with different diameters (for the δ formula h will be mixed with the test material, Table 3... Bu, using the cursor; percentage of value) is shown below. The average diameter of the test material is the average diameter, and the results are shown in the long and short diameters of the test piece, and the average value of the time is calculated. In Table 4 below, 'also indicates the average of the results of the mass per unit of the test material and the mass of 20 samples measured by 2012-11264. The degree of viscosity of the polymer was impregnated in the liquid (mercury). The unit mass of the test material is the value. The apparent density of the test material is determined by measuring the buoyancy and using a laboratory-scale small heating furnace (the temperature in the furnace is 145 〇. [The materials obtained by heating the average diameter are different, and the investigation is made. The time required for the reduction or melting of the iron ore contained in the test material (reaction time The measurement results of the reaction time are shown in Table 4 below. The relationship between the average straight edge (Dp) of the test material and the reaction time is shown in Fig. 5. The curve shown by the broken line in Fig. 5 represents the approximate curve of the plotted point, based on the quadratic formula of the average diameter of the test material. As can be seen from Fig. 5, the larger the average diameter of the test material, the longer the reaction time According to the results of the above Experimental Example 1, the reaction time or the product recovery rate was normalized, and the comprehensive evaluation changed the distance between the test materials (the following Experimental Example 2) or the deposition density of the test materials (the following experimental examples) 3) Productivity. [Table 1] — Composition of iron ore (clear %) - Total amount of Fe FeO Si02 CaO AI2O3 MgO MnO T1O2 P s 67.73 29.40 4.54 0.42 0.21 0.47 0.34 0.07 0.018 0.002 [Table 2] Stone carbon composition p ί quantity 0/ ) Ash Volatile Fixed Carbon 77.21 16.65 6.14 Total 100 201 211 264 [Table 3] __ # test material bonded composition (mass%) of carbon binder auxiliary raw stone ore 71.95 17.01 0.90 11.55 [Table 4]
No. 平均直經 (mm) 單位質量 (g/個） 視密度 (g/cm3) 反應時間 (分鐘） 1 ~173 ~~ 6.06 2.23 8.7 2 18.8 7.58 2.19 8.8 3 ~~\9A~~ 8.46 2.21 9.0 4 21.3 11.16 2.21 10.0 5 _ 23.1—~1 14.60 2.27 10.7 25.2 18.77 2.24 12.0 7 27.0 22.98 2.23 13.2 [實驗例2 ] 於實驗例2中’綜合調查：「使用實機之移動床型還原 熔融爐，使爐床上之供試材之鋪設密度固$，對平均直徑 為16.〇〜28.0随（1.6〇〜28〇咖）之供試材進行加埶而^ 造粒狀金屬鐵時」之供試材之平均直徑對粒狀金屬鐵之生 產性所造成之影響。 使用旋轉爐床爐作為移動床型還原熔融爐，以爐床上 之供試材之鋪設密度成為G.66之方式，將上述供試材供給 至爐床上並加熱’使鐵礦石還原熔融而製造粒狀金屬鐵。 爐内之溫度係將前半區域設定為14〇〇t，將後半區域設定 為1470°C。所謂前半區域，係指實施供試材中之鐵礦石之· 固體還原之區@ ’所謂後半區域，係指於供試材中生成並 20 201211264 炼融之微小還原鐵進行滲破 炼渣分離之區域。 溶解’最終凝聚並與熔鐵及 爐床上之供試材之舖設密度，係調整供試材向爐内之 ，給量與爐床之移動速度（旋轉速度）而控制。即以於 根據上述預備實驗之結果而設定之環境條件之加熱區域 内」鐵礦石進行還原熔融之方式，確定爐床之移動速度， 考慮該移動速度而調整上述供財之供給量，將爐床上之 供武材之鋪設密度控料G.66e於下述表5中，將供試材 彼此之距離r作為參考值表示。 根據上述式（3 )算出使各供試材還原熔融而製造粒狀 金屬鐵時之生產性，將Nq12之供試材（標準黏聚物）之 生產性作為基準（生產性指數1〇〇)，以相對值（生產性指 數）表示各供試材之生產性。將各供試材之生產性指數示 於下述.表5。另外，將供試材之平均直徑與生產性指數之關 係示於圖6。 由圖6可知’於使爐床上之鋪設密度固定之情形時， 藉由將供試材之平均直徑增大至17.5 mm以上，比供試材 之平均直徑為16.0 mm時更能改善生產性。即，隨著增大 供試材之平均直徑’生產性逐漸提高，供試材之平均直徑 為22.0 mm時’生產性指數成為最大值。 但是’若增大供試材之平均直徑超過26 〇 mm，則存在 粒狀金屬鐵之生產性逐漸惡化之傾向。認為生產性之所以 惡化’係因為由於供試材變大，故而反應時間變長。因此， 可知於鋪設密度為固定之情形時，藉由將供試材之平均直 21 201211264 徑調整為17_5〜26.〇111111之間，比使用平均直徑為16〇1〇1^ 之供試材更能改善生產性。 [表5]No. Average straight (mm) Unit mass (g/piece) Visual density (g/cm3) Reaction time (minutes) 1 ~173 ~~ 6.06 2.23 8.7 2 18.8 7.58 2.19 8.8 3 ~~\9A~~ 8.46 2.21 9.0 4 21.3 11.16 2.21 10.0 5 _ 23.1—~1 14.60 2.27 10.7 25.2 18.77 2.24 12.0 7 27.0 22.98 2.23 13.2 [Experimental Example 2] In Experimental Example 2 'Integrated investigation: 'Use a moving bed type reduction melting furnace of a real machine to make The laying density of the test material on the hearth is fixed at $1, for the test piece where the average diameter is 16.〇~28.0 with (1.6〇~28〇), and when the granulated metal iron is added The effect of the average diameter on the productivity of granular metallic iron. The rotary hearth furnace is used as a moving bed type reduction melting furnace, and the test material is supplied to the hearth in the manner of the coating density of the test material on the hearth, and the steel material is supplied to the hearth and heated to reduce or melt the iron ore. Granular metal iron. The temperature in the furnace was set to 14 〇〇t for the first half and 1470 °C for the second half. The so-called first half area refers to the area where the solid ore reduction of iron ore in the test material is carried out @ 'the so-called second half area, which refers to the separation of the slag and slag formed by the micro-reduced iron produced in the test material and 20 201211264 refining. The area. The dissolution density of the final 'coagulation' and the molten iron and the test material on the hearth is controlled by adjusting the amount of the test material to the furnace, the amount of movement and the moving speed (rotation speed) of the hearth. That is, the iron ore is reduced and melted in the heating zone of the environmental conditions set according to the results of the preliminary experiment, and the moving speed of the hearth is determined, and the supply amount of the above-mentioned supply is adjusted in consideration of the moving speed. The laying density control material G.66e for the arable material on the bed is shown in Table 5 below, and the distance r between the test materials is indicated as a reference value. According to the above formula (3), the productivity of the test material is reduced and melted to produce granular metallic iron, and the productivity of the test material (standard clay) of Nq12 is used as a reference (productive index 1 〇〇). The relative value (productivity index) indicates the productivity of each test material. The productivity index of each test material is shown below. Table 5. Further, the relationship between the average diameter of the test material and the productivity index is shown in Fig. 6. As can be seen from Fig. 6, when the laying density of the furnace bed is fixed, the productivity is improved by increasing the average diameter of the test material to 17.5 mm or more, which is larger than the average diameter of the test material of 16.0 mm. That is, the productivity is gradually increased as the average diameter of the test piece is increased, and the productivity index becomes the maximum when the average diameter of the test piece is 22.0 mm. However, if the average diameter of the test piece is increased by more than 26 〇 mm, the productivity of the granular metal iron tends to deteriorate. It is considered that the reason why the productivity is deteriorated is because the reaction time becomes long because the test material becomes large. Therefore, it can be seen that when the laying density is fixed, the average straight diameter 21 201211264 of the test material is adjusted to be between 17_5 and 26. 〇111111, and the test material having an average diameter of 16〇1〇1^ is used. It can improve productivity. [table 5]
No. 平均直徑 (cm) 距離r (cm) 鋪設密度 (-) 生產性指數 11 1.60 0.37 0.66 0.93 12 1.75 0.37 0.66 1.00 13 1.81 0.42 0.66 ΓοΓ~~' 14 1.90 0.44 0.66 L05 15 2.00 0.46 0.66 L07 16 2.20 0.50 0.66 1Ό8~~' 17 2.40 0.55 0.66 1.05 18 2.60 0.60 0.66 Γ im ~" 19 2.80 0.64 0.66 0.95 [實驗例3] 於實驗例3中，調查：「假定平均直徑為16.〇〜32 〇mm (1.60〜2.80 cm)之供試材，使用實機之移動床型還原熔 融爐，使爐床上之供試材彼此之距離r固定（〇 42 cm)，改 變供試材之鋪設密度進行加熱而製造粒狀金屬鐵時」之供 試材之鋪設密度對粒狀金屬鐵之生產性所造成之影響。 此事例係：使用旋轉爐床爐作為移動床型還原熔融 爐，將下述表6所示之平均直徑之供試材供給至爐床上進 订加熱’使鐵礦石還原炫融而製造粒狀金屬鐵之情形。爐 内之力，、、、條件與上述實驗例2相同。將爐床上之供試材之 鋪設密度示於下述表6。 根據上述或「2@ · ^ 算出使各供試材還原熔融而製造粒狀 金屬鐵時之生產，祕 肢 斗m , 22之供試材（標準黏聚物）之 生產性作為基準M 、 •)’以相對值（生產性指數）表示各 22 201211264 供3式材之生產性。將各供試材之生產性指數示於下述表6。 另外’將供試材之平均直徑與生產性指數之關係示於圖7。 由下述表6及圖7可知，於使供試材彼此之距離r固定 之情形時’藉由將供試材之平均直徑增大至丨7 5 mm以上， 可增大爐床上之供試材之鋪設密度。另外，增大供試材之 平均直徑比供試材之平均直徑為16G時更能改善粒狀金屬 鐵之^產性。即，隨著增大供試材之平均直徑，生產性逐 漸提同’供试材之平均直徑為24 G随時生產性指數成為 最大值。 仁疋，右増大供試材之平均直徑至超過24 〇爪爪，則存 在粒狀金屬鐵之生產性逐漸惡化之傾向H生產性之所 、會降低係因為由於供試材變大，故而反應時間變長。 因此，可知藉由將供試材之平均直徑調整為17 5〜32〇咖 之間，比使用平均直徑兔】Α Λ 』旦瓜為16.0 mm之供試材更能改善生 性。 | 23 201211264 [表6]No. Average diameter (cm) Distance r (cm) Laying density (-) Productivity index 11 1.60 0.37 0.66 0.93 12 1.75 0.37 0.66 1.00 13 1.81 0.42 0.66 ΓοΓ~~' 14 1.90 0.44 0.66 L05 15 2.00 0.46 0.66 L07 16 2.20 0.50 0.66 1Ό8~~' 17 2.40 0.55 0.66 1.05 18 2.60 0.60 0.66 Γ im ~" 19 2.80 0.64 0.66 0.95 [Experimental Example 3] In the experimental example 3, investigation: "Assume that the average diameter is 16. 〇~32 〇mm (1.60~2.80 cm) of the test materials, using a moving bed type reduction melting furnace of the actual machine, so that the distance between the test materials on the hearth is fixed (〇42 cm), and the density of the test materials is changed to be heated. When the granular metal iron is produced, the density of the test material is affected by the productivity of the granular metallic iron. In this case, a rotary hearth furnace is used as a moving bed type reduction melting furnace, and the test piece of the average diameter shown in Table 6 below is supplied to the hearth to be ordered and heated to reduce the iron ore and produce a granular shape. The case of metal iron. The forces, conditions, and conditions in the furnace were the same as in Experimental Example 2 described above. The packing density of the test pieces on the hearth is shown in Table 6 below. According to the above or "2@ · ^, the production of granular metal iron is produced by reducing and melting each test material, and the productivity of the test material (standard clay) of the secret limbs m and 22 is used as the reference M. ) 'The relative value (productive index) indicates the productivity of each of the 22 201211264 for the 3 formulas. The productivity index of each test material is shown in the following Table 6. In addition, 'the average diameter and productivity of the test materials The relationship between the indices is shown in Fig. 7. As can be seen from the following Table 6 and Fig. 7, when the distance r between the test materials is fixed, 'by increasing the average diameter of the test material to 丨7 5 mm or more, The packing density of the test material on the hearth can be increased. In addition, increasing the average diameter of the test material can improve the productivity of the granular metal iron when the average diameter of the test material is 16G. The average diameter of the large test material, the productivity is gradually increased with the average diameter of the test material is 24 G, and the productivity index becomes the maximum. The average diameter of the test material of the right ridge and the right ridge is more than 24 〇 claws. There is a tendency for the productivity of granular metallic iron to gradually deteriorate. Because the test material becomes larger, the reaction time becomes longer. Therefore, it can be seen that by adjusting the average diameter of the test material to between 17 5 and 32 〇 coffee, the average diameter of the rabbit is used. The 16.0 mm test material is more effective. | 23 201211264 [Table 6]
No. 平均直徑 距離r 鋪設密度 生產性指數 (cm) (cm) (-) 21 1.60 0.42 0.63 0.89 11 1.75 0.42 0.65 1.00 2ό 1.81 0.42 0.66 1.04 24 1.90 0.42 0.67 1.08 2t> 2.00 0.42 0.69 1.12 2b 2.20 0.42 0.71 1.17 2/ 2.40 0.42 0.73 1.17 28 2.60 0.42 0.74 1.15 29 2.80 0.42 0.76 1.10 iU 3.00 0.42 0.77 1.05 31 3.20 0.42 0.78 0.99 ’如上述實驗例2所 綜合上述實驗例2、3之結果可知 示，若使用平均直徑較大之黏聚物（例如平均直徑超過28 〇 mm之黏聚物）’則於鋪設密度為固定之情形時，存在粒狀 金屬鐵之生產性降低之情況，但如上述實驗例3所示，若 提高鋪設密度，則即便使用例如平均直徑超過28 〇 mm之 黏聚物，亦可提高生產性。即可知：將爐床上之黏聚物（供 •式材）之鋪设密度设為〇·5以上進行加熱時，可藉由將平均 直徑為17.5 性。換言之 mm以上之黏聚物供給至爐床上而提高生產 17.5 mm以上之黏聚 可知若準備平均直徑為 物，將爐床上之黏聚物之鋪設密度設為〇 5以上於爐内進行 加熱，則可生產性良好地製造粒狀金屬鐵。 [產業上之可以用性] 根據本發明’可提高粒狀金屬之生產性。 【圖式簡單說明】 圖1係示意性地表示鋪滿於爐床上之黏聚物之平面圖。 24 201211264 圖2係表示鋪滿平均直徑為18.2 黏聚物時之情 況之圖式代用照片。 圖3係表示黏聚物彼此之距離r與投影面積率或鋪設密 度之關係之圖表。 圖4係表示鋪設密度與黏聚物向爐内之供給量之關係 之圖表。 圖5係表示供試材（黏聚物）之平均直徑（)與反 應時間之關係之圖表。 圖6係表示使黏聚物之鋪設密度固定而製造粒狀金屬 鐵時之黏聚物的平均直徑與生產性指數之關係之圖表。 圖7係表示使爐床上之黏聚物（供試材）彼此之距離r 固定而製造粒狀金屬鐵時之黏聚物的平均直徑與生產性指 數之關係之圖表。 【主要元件符號說明】No. Average diameter distance r Laying density Productivity index (cm) (cm) (-) 21 1.60 0.42 0.63 0.89 11 1.75 0.42 0.65 1.00 2ό 1.81 0.42 0.66 1.04 24 1.90 0.42 0.67 1.08 2t> 2.00 0.42 0.69 1.12 2b 2.20 0.42 0.71 1.17 2/ 2.40 0.42 0.73 1.17 28 2.60 0.42 0.74 1.15 29 2.80 0.42 0.76 1.10 iU 3.00 0.42 0.77 1.05 31 3.20 0.42 0.78 0.99 'As shown in the above Experimental Example 2, the results of the above Experimental Examples 2 and 3 can be seen, if the average diameter is used. Larger cohesives (for example, agglomerates having an average diameter of more than 28 〇mm) have a situation in which the productivity of granular metallic iron is lowered when the laying density is fixed, but as shown in the above Experimental Example 3. If the packing density is increased, productivity can be improved even if a binder having an average diameter of more than 28 mm is used. It can be seen that when the density of the binder (supply) of the furnace bed is set to 〇·5 or more, the average diameter is 17.5. In other words, when the binder of more than mm is supplied to the hearth to increase the cohesion of 17.5 mm or more, it is known that if the average diameter is prepared, the packing density of the binder on the hearth is set to 〇5 or more and heated in the furnace. Granular metallic iron can be produced with good productivity. [Industrial Applicability] According to the present invention, the productivity of the granular metal can be improved. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view schematically showing a binder which is spread on a hearth. 24 201211264 Figure 2 shows a photograph of a substitute for a situation where the average diameter is 18.2. Fig. 3 is a graph showing the relationship between the distance r of the binders from each other and the projected area ratio or the laying density. Fig. 4 is a graph showing the relationship between the laying density and the amount of the binder supplied to the furnace. Fig. 5 is a graph showing the relationship between the average diameter () of the test material (viscosity) and the reaction time. Fig. 6 is a graph showing the relationship between the average diameter of the binder and the productivity index when the packing density of the binder is fixed to produce the granular metal iron. Fig. 7 is a graph showing the relationship between the average diameter of the binder and the productivity index when the distance between the binders (test materials) on the hearth is fixed to produce granular metal iron. [Main component symbol description]
Dp 黏聚物之平均直徑 r 黏聚物彼此之距離 25Dp The average diameter of the binder r The distance between the binders 25