把吸油值为1.64 mL/g的光纤预制棒废料粉末用草酸酸洗后置于600 ℃下煅烧，除去杂质部分，得到了吸油值为2.1 mL/g的白炭黑。为探究光棒废料粉末经草酸酸洗、高温煅烧后吸油值提高的机理，采用激光粒度分析仪和FT-IR对产品进行表征，发现粉末的粒径相比于原始废料粉末显著增大，且在位于1 480 cm-1处有新红外吸收峰，预测此峰可能为碳酸基团（CO3）中的C—O伸缩振动峰。通过Gaussian 09程序计算得到了粉末颗粒间的成键模型，该模型的红外光谱计算结果与实验光谱基本相符，支持了对新吸收峰归属的预测。光棒废料粉末在草酸酸洗、600 ℃煅烧后吸油值提高的原因可能是，草酸与不同颗粒的表面羟基发生酯化反应，然后高温脱去一氧化碳，形成由碳酸基团（CO3）连接二氧化硅颗粒的三维网状的二次结构，在增大粒径的同时也改善了空间孔隙结构，从而提高了产品的吸油值。

The optical fiber preform waste powder with the oil absorption value of 1.64 mL/g was acid?鄄washed with oxalic acid and then calcined at 600 ℃ to remove the impurity fraction，and white carbon black with oil absorption value of 2.1 mL/g was obtained.In order to explore the mechanism of the process，the product was characterized by LDSA and FT-IR.It was found that the particle size of the powder was significantly increased compared with the original waste powder，and there was a new infrared absorption peak at 1 480 cm-1，which was predicted to be a C—O stretching vibration peak in the CO3 group. The model of the bond structure between the powder particles was obtained by Gaussian 09 program simulation.The infrared spectrum simulation of the model was basically consistent with the experimental ones，which supported the prediction of the attribution of the new absorption peak.The reason why the oil absorption value of the optical fiber preform waste powder was improved after oxalic acid pickling and calcination at 600 ℃ may be that the oxalic acid was esterified with the hydroxyl groupson the surface of different particles，and then the CO was removed at a high temperature to form a secondary structure of three?鄄dimensional network which was composed of silica particles being connected with CO3 groups，which not only increased the particle size but also improved the pore structure.Therefore，the oil absorption value of the product was improved.