(中南大學(xué) 資源加工與生物工程學(xué)院，戰(zhàn)略含鈣礦物資源清潔高效利用湖南省重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 探索礦物晶體斷裂及晶面暴露機(jī)制，對(duì)于精準(zhǔn)調(diào)控礦物表面性質(zhì)具有重要指導(dǎo)意義。前期提出的斷裂鍵密度Db法，可準(zhǔn)確解析具有一種類型斷裂鍵的礦物/材料晶體的斷裂機(jī)制。然而，對(duì)于具有兩種及以上類型斷裂鍵的晶體，需要探索新方法。本文以具有3種類型斷裂鍵的鋯石晶體為例，采用第一性原理計(jì)算與Bader電荷分析，提出基于鍵級(jí)權(quán)重的晶面斷裂能密度(Sc)方法，快速評(píng)估鋯石沿各晶面斷裂的難易度，揭示晶面暴露規(guī)律。晶體化學(xué)鍵鍵能計(jì)算分析表明，鋯石晶體中各化學(xué)鍵鍵能大小順序?yàn)镾i—O(6.00 eV)＞Zr—Oβ(2.87 eV)＞Zr—Oα(1.60 eV)。晶面斷裂能密度Sc計(jì)算表明，鋯石晶體沿(200)面最易斷裂，因此(200)面最易暴露。此外，Sc與表面能有良好相關(guān)性，在一定條件下，晶面斷裂能密度Sc可用于快速評(píng)價(jià)晶面穩(wěn)定性和反應(yīng)性。
關(guān)鍵字: 鋯石；晶面斷裂能密度；斷裂鍵密度；表面反應(yīng)性
（Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources, School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:Exploring the mechanism of crystal fracture and crystal plane exposure is important for accurately controlling the surface properties of minerals. The fracture mechanism of mineral crystals with one type of fracture bond can be accurately analyzed by the surface fracture bond density Db method proposed by the author earlier. However, for crystals with two or more types of broken bonds, new methods need to be explored. Taking zircon crystal with two types of fracture bonds as an example, this paper proposes a method of crystal plane fracture energy (Sc) based on bond order weight by using first principles calculation and Bader charge analysis, which can quickly evaluate the degree of fracture difficulty of zircon along each facet and reveal the rules of surface exposure. The calculation and analysis of crystal chemical bond energy show that the size of chemical bond energy in zircon crystal is Si—O (6.00 eV)＞Zr—Oα (2.87 eV)＞Zr—Oβ (1.60 eV). The calculation of fracture energy shows that zircon crystals are most easily fractured along the (200) plane, so the (200) plane is the most easily exposed. In addition, we found a good correlation between the Sc and the surface energy, and the crystal plane fracture energy can be used to quickly evaluate the stability and reactivity of the facet under certain conditions.
Key words: zircon; crystal plane fracture energy; broken bonds density; surface reactivity
