新型搅拌器结构设计及其关键参数对性能的影响

设计了一种新型带包圈型六叶平直叶桨式搅拌器,建立其结构和流场模型,利用数值模拟方法对搅拌容器内部的固-液两相流场进行模拟计算,通过分析液相速度矢量图和固含率云图,研究关键参数对新型搅拌器的性能影响。结果表明:搅拌器包圈高度、搅拌转速、安装高度和桨叶直径对搅拌器的混合效果具有重要影响,在搅拌器选型和搅拌器工作时,选择合适的参数对搅拌效果至关重要。

新型氧化铝吨袋包装机的研制

本文就ADB69型吨袋包装机的性能、结构及工作原理,以及存在的问题和改进措施及基本运行情况进行了概述,ADB69型吨袋包装机完全达到了预期设计目标,具有较大的推广价值。

Experimental studies of melt-peridotite reactions at 1–2 GPa and 1250–1400°C and their implications for transforming the nature of lithospheric mantle and for high-Mg signatures in adakitic rocks

Experiments of the melt-peridotite reaction at pressures of 1 and 2 GPa and temperatures of 1250–1400°C have been carried out to understand the nature of the peridotite xenoliths in the Mesozoic high-Mg diorites and basalts of the North China Craton,and further to elucidate the processes in which the Mesozoic lithospheric mantle in this region was transformed.We used Fuxin alkali basalt,Feixian alkali basalt,and Xu-Huai hornblende-garnet pyroxenite as starting materials for the reacting melts,and lherzolite xenoliths and synthesized harzburgite as starting materials for the lithospheric mantle.The experimental results indicate that:(1)the reactions between basaltic melts and lherzolite and harzburgite at 1–2 GPa and 1300–1400°C tended to dissolve pyroxene and precipitate low-Mg#olivine(Mg#=83.6–89.3),forming sequences of dunite-lherzolite(D-L)and duniteharzburgite(D-H),respectively;(2)reactions between hornblende-garnet pyroxenite and lherzolite at 1 GPa and 1250°C formed a D-H sequence,whereas reactions at 2 GPa and 1350°C formed orthopyroxenite layers and lherzolite;and(3)the reaction between a partial melt of hornblende-garnet pyroxenite and harzburgite resulted in a layer of orthopyroxenite at the boundary of the pyroxenite and harzburgite.The reacted melts have higher MgO abundances than the starting melts,demonstrating that the melt-peridotite reactions are responsible for the high-Mg#signatures of andesites or adakitic rocks.Our experimental results support the proposition that the abundant peridotite and pyroxenite xenoliths in western Shandong and the southern Taihang Mountains might have experienced multiple modifications in reaction to a variety of melts.We suggest that melt-peridotite reactions played important roles in transforming the nature of the Mesozoic lithospheric mantle in the region of the North China Craton.

Effects of melt percolation on the Re-Os systematics of continental mantle lithosphere: A case study of spinel peridotite xenoliths from Heilongjiang, NE China

Os isotope ratios of mantle peridotites have been considered to be largely immune to recent melt-rock interaction. However, Os isotope ratios and PGE (Platinum group elements) concentrations of the Yong'an xenoliths have been significantly modified by melt percolation, and are not suitable for determining the formation age of lithosphere mantle in Yong'an. In this study, the Yong'an spinel peridotite xenoliths are divided into two groups: N-Type and E-Type. The N-Type group including cpx (clinopyroxene)-poor lherzolite and harzburgite, shows a large variation of Cr#(sp) (13.2-48) and sulfur contents (from 171 ppm to below detection limit), whereas the E-Type peridotites are mainly refractory harzburgites and are characterized by high Cr#(sp) (35.3-42.2) and overall low sulfur contents (below 51 ppm). Both types show similar major and REE (rare earth element) patterns. Furthermore, the N-Type peridotites display a restricted range of iridium-group PGE (IPGE), Os/Ir and Ru/Ir ratios (Os/Ir = 0.64-1.12, Ru/Ir = 1.52-1.79) and variable palladium-group PGE (PPGE) contents (3.4-14.9 ppb), whereas the E-Type peridotites show a large variation of Os/Ir and Ru/Ir ratios (Os/Ir = 0.33-0.84, Ru/Ir = 0.94-1.6), and a restricted range of PPGE (4.3-6.9 ppb). 187Os/188Os ratios of E-Type peridotites are higher than those of N-Type peridotites at comparable fertility levels. These results suggest that N-Type peridotites may have been overprinted by metasomatism via small melt fractions, in which the percolation of the volatile-rich, small melt fractions only resulted in LILE (large ion lithophile element) enrichment of clinopyroxene, and their whole rock PGE contents and Re-Os isotope values were little changed. Moreover, E-Type peridotites may have been modified by melt-rock reaction involving relatively large melt fractions, which may result in the formation of secondary cpx and olivine and the removal of IPGE-bearing minerals such as Ru-Os-(Ir) alloys or laurite, followed by precipitation of secondary sulfides from melt with radiogenic isotopic signature.

Ultradeep diamonds originate from deep subducted sedimentary carbonates

Diamonds are renowned as the record of Earth's evolution history.Natural diamonds on the Earth can be distinguished in light of genetic types as kimberlitic diamonds(including peridotitic diamonds and eclogitic diamonds),ultrahigh-pressure metamorphic diamonds and ophiolitic diamonds.According to the inclusion mineralogy,most diamonds originated from continental lithospheric mantle at depths of 140-250 km.Several localities,however,yield ultradeep diamonds with inclusion compositions that require a sublithospheric origin(>~250 km).Ultradeep diamonds exhibit distinctions in terms of carbon isotope composition,N-concentration,mineral inclusions and so on.The present study provides a systematic compilation concerning the features of ultradeep diamonds,based on which to expound their genesis affinity with mantle-carbonate melts.The diamond-parental carbonate melts are proposed to be stemmed from the Earth's crust through subduction of oceanic lithosphere.Ultradeep diamonds are classified into a subgroup attaching to kimberlitic diamonds grounded by formation mechanism,and present connections in respect of carbon origin to eclogitic diamonds,ultrahigh-pressure metamorphic diamonds and ophiolitic diamonds.