The results indicated that poor casting and material quality were the cause of bursting.

结果表明，材质和铸造质量差是其开裂的主要原因。

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Metallurgical lime is a necessary auxiliary material for the iron and steel production and its good or poor quality has direct influence on the quality of iron and steel product.

冶金石灰是钢铁生产必不可少的辅助材料，其质量的优劣直接影响钢铁产品的质量。

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But the poor quality of copper, copper material which contains impurities, broken into two parts on hand curved, which can be seen in black impurities, this is definitely not used.

但是劣质铜，铜材质里面含有杂质，用手一弯就断成两截，里面可以看到有黑色杂质，这个是绝对不能采用的。

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But the poor quality of copper, copper material which contains impurities, broken into two parts on hand curved, which can be seen in black impurities, this is definitely not used.

但是劣质铜，铜材质里面含有杂质，用手一弯就断成两截，里面可以看到有黑色杂质，这个是绝对不能采用的。

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