萘是煤焦油中含量高的雙環(huán)化合物，是有機合成工業(yè)中重要的原料之一，是生產活性染料、酸性染料、直接染料、炸藥、H-酸、β-萘酚、苯酐等精細化工產品必需原料。目前國內大部分焦化廠只生產工業(yè)萘或壓榨萘，以此為原料生產的產品，雜質較多，給分離精制增加困難。因此精萘十分緊缺，一直供不應求。

Naphthalene is a bicyclic compound with high content in Coal tar. It is one of the important raw materials in the organic synthesis industry. It is used to produce Reactive dye, acid dyes, direct dyes, explosives, H-acid β- Essential raw materials for fine chemical products such as naphthol and phthalic anhydride. At present, most coking plants in China only produce industrial naphthalene or pressed naphthalene. The products produced from this raw material have many impurities, which increases the difficulty of separation and refining. Therefore, refined naphthalene is very scarce and has been in short supply.

目前，國內精萘已實現工業(yè)化生產的主要有區(qū)域熔融法、分步熔融結晶（箱法）及化學法等。下面精萘廠家為您分析：

At present, the main industrial production methods for refined naphthalene in China include regional melting method, step-by-step melting crystallization (box method), and chemical method. The following refined naphthalene manufacturers will analyze for you:

區(qū)域熔融工藝的特點是：精萘純度高、處理量大，基本上沒有環(huán)境污染。但是，技術復雜、設備一次投資相當大。精萘機的操作條件控制要求相當嚴格。各段溫度梯度控制精度要求在05℃以內。目前采用該技術常由電腦控制系統(tǒng)。相應地操作人員的技術素質要求很高，操作程序不易掌握。

The characteristics of regional melting process are: high purity of refined naphthalene, large processing capacity, and basically no environmental pollution. However, the technology is complex and the one-time investment in equipment is considerable. The operating conditions control requirements of the naphthalene refining machine are quite strict. The temperature gradient control accuracy of each section is required to be within 05 ℃. Currently, this technology is often controlled by a computer system. Correspondingly, the technical quality requirements of operators are high, and the operating procedures are not easy to master.

熔融分步結晶法初為法國Proabd公司專利，六十年代先后在英國和捷克建廠投入生產。但此后未在國際上進一步推廣。其主要原因是設備龐大，操作周期長。

The melting step crystallization method was initially patented by Proabd Company in France and was put into production in the UK and Czech Republic in the 1960s. But it has not been further promoted internationally since then. The main reason is that the equipment is large and the operation cycle is long.

化學法萘精制工藝已生產多年，面臨淘汰。主要原因是工藝流程太長，萘的回收率較低。僅洗滌過程中，純萘的損失量約5%。生產需要較大量的濃硫酸和燒堿，而且一般不能回收利用，所以，環(huán)境污染嚴重，工人操作條件比較惡劣，設備腐蝕嚴重，生產成本較高。

The chemical naphthalene refining process has been in production for many years and is facing elimination. The main reason is that the process flow is too long and the recovery rate of naphthalene is low. During the washing process alone, the loss of pure naphthalene is about 5%. Production requires a large amount of concentrated sulfuric acid and caustic soda, and generally cannot be recycled. Therefore, environmental pollution is severe, workers' operating conditions are relatively poor, equipment corrosion is severe, and production costs are high.

本發(fā)明的目的是提供一種足以克服上述缺點的溶劑結晶法制取精萘工藝，它設備簡單，操作容易，周期短，產品質量穩(wěn)定，無環(huán)境污染。

The purpose of the present invention is to provide a solvent crystallization process for preparing refined naphthalene that is sufficient to overcome the aforementioned drawbacks. The process has simple equipment, easy operation, short cycle, stable product quality, and no environmental pollution.

1.一種溶劑結晶法制取精萘工藝，其特征是所用原料為萘渣或焦油渣，蒸餾截取210～230℃時的餾分，也可直接采用工業(yè)萘或水萘，將回收的餾分或工業(yè)萘、水萘置入反應釜內，再加入有機溶劑，其用量與原料用量的重量比為2.5～3.5∶1，加溫至70～80℃，使全部原料溶解，然后逐漸降溫至30～15℃，重新結晶，再進入離心機分離，將分離出的溶劑回收再用，分離出的精萘干燥后即成產品。

1. A solvent crystallization process for producing refined naphthalene, characterized in that the raw material used is naphthalene residue or tar residue, and the distillate at 210~230 ℃ is cut off by distillation. Industrial naphthalene or water naphthalene can also be directly used. The recovered fraction, industrial naphthalene, and water naphthalene are placed in a reactor, and then organic solvents are added. The weight ratio of the amount to the amount of raw materials is 2.5~3.5:1. The process is heated to 70~80 ℃ to dissolve all the raw materials, and then gradually cooled to 30~15 ℃, Recrystallize and then enter a centrifuge for separation. The separated solvent is recycled and reused, and the separated naphthalene is dried to form the product.

國內精萘已實現工業(yè)化生產的主要方法相關內容就講解到這里了，希望能夠給您好的幫助，更多事項就來我們網站http://m.cdjdhxt.cn咨詢吧！

That's all for the main methods of industrialized production of refined naphthalene in China. We hope to provide you with good help. For more information, please come to our website http://m.cdjdhxt.cn Consult!