本文關(guān)鍵詞：鎂渣基緩釋性硅鉀肥的制備及性能研究　出處：《山西大學(xué)》2016年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 鎂渣 硅鉀肥 重金屬 緩釋性 盆栽試驗(yàn)

【摘要】：鎂及鎂合金是重要的戰(zhàn)略儲備物質(zhì),我國是最大的鎂生產(chǎn)國和出口國。鎂冶煉主要采用皮江法煉鎂,每生產(chǎn)1噸金屬鎂,產(chǎn)生6～8噸的鎂渣,鎂渣的大量排放堆積,不僅占用土地,也對周圍環(huán)境造成極大影響,制約了鎂產(chǎn)業(yè)的健康持續(xù)發(fā)展。此外,我國鉀肥資源嚴(yán)重不足,鉀肥流失嚴(yán)重,造成鉀資源的浪費(fèi)和環(huán)境污染。本研究基于鎂渣的理化特性和環(huán)境安全性,利用碳酸鉀改性鎂渣,制備了一種新型緩釋性硅鉀肥,并對硅鉀肥的制備工藝、結(jié)晶性能、養(yǎng)分釋放特性、肥效和農(nóng)業(yè)安全性進(jìn)行了系統(tǒng)的理論分析和實(shí)驗(yàn)研究。1、以皮江法還原鎂渣(MS)為研究對象,通過XRD、FTIR、TG-DT、SEM-EDS等對其進(jìn)行表征分析,分析了鎂渣的理化特性和環(huán)境風(fēng)險(xiǎn),結(jié)果表明,鎂渣是一種細(xì)顆粒粉末狀的堿性廢渣,顆粒粒徑以147μm為主,各粒徑鎂渣的化學(xué)組成存在差異,鎂渣的比表面積、表觀密度、孔徑與硅酸鹽水泥特性相近,不適合用于孔吸附材料,較適合用于建材開發(fā)；鎂渣的主要化學(xué)組成為CaO、SiO2、MgO、Fe2O3、 Al2O3,主要物相為β-Ca_2SiO_4、γ-Ca_2SiO_4、MgO和CaO,次要組分相為Ca(OH)2、 Mg(OH)2、CaCO3、MgCO3,主要以穩(wěn)定的礦物形態(tài)存在,可溶性組分很少；鎂渣中重金屬含量符合有機(jī)-無機(jī)復(fù)混肥國家標(biāo)準(zhǔn),放射性核素比活度、內(nèi)照射指數(shù)與外照射指數(shù)達(dá)到A類裝飾裝修材料國家標(biāo)準(zhǔn)的放射性要求(IRa≤1.0,Iγ≤1.3)。鎂渣中重金屬主要以穩(wěn)定的有機(jī)態(tài)和殘?jiān)鼞B(tài)存在,鎂渣中重金屬與氟的浸出濃度均遠(yuǎn)低于國內(nèi)外危險(xiǎn)廢物標(biāo)準(zhǔn)限值,即使在最不利條件下,鎂渣中重金屬的有效浸出量仍遠(yuǎn)低于毒性鑒別的最低限值,且鎂渣中含量最高的Cr主要以毒性較小的Cr3+存在；Cr、Cu和Ni的浸出量與浸出劑的pH值表現(xiàn)出強(qiáng)的相關(guān)性,浸出質(zhì)量濃度均低于危險(xiǎn)廢物標(biāo)準(zhǔn)限值。因此,鎂渣中含有土壤和作物所需有益元素,環(huán)境安全性高,污染風(fēng)險(xiǎn)低,可以進(jìn)行農(nóng)業(yè)資源化利用。2、通過單因素實(shí)驗(yàn)與正交試驗(yàn)相結(jié)合考察了碳酸鉀改性鎂渣制備硅鉀肥的工藝。首先以單因素實(shí)驗(yàn)確定了正交試驗(yàn)的考察因子及水平；然后以總硅中活性硅含量(AST)和硅鉀肥的初期溶出率(Kin)為考察指標(biāo),采用正交試驗(yàn)對硅鉀肥制備工藝進(jìn)行了優(yōu)化。結(jié)果表明,各因子對AST和Kin影響的大小次序分別為加熱溫度鎂渣粒徑保溫時(shí)間K_2O含量和鎂渣粒徑加熱溫度保溫時(shí)間K_20含量,其中鎂渣粒徑與加熱溫度對AST和Kin影響最為顯著(α=0.05),確定硅鉀肥制備的最優(yōu)實(shí)驗(yàn)方案為：選用風(fēng)冷鎂渣,K_2O添加量為15～25%,加熱溫度1300℃,保溫時(shí)間60min,鎂渣粒徑≤80μm,冷卻方式為風(fēng)冷；所制硅鉀肥的K釋放率符合國標(biāo)《緩釋肥料》中“部分緩釋肥料”要求,總硅中有效硅含量約為鎂渣的2.5倍,鉀收率為90%左右；鎂渣中Fe2O3、Al2O3的組成變動對硅鉀肥性能無明顯影響,MgO含量的增加可改善硅鉀肥的性能。3、通過XRD、SEM以及SEM-EDS測試了不同條件所制硅鉀肥的結(jié)晶性能,結(jié)果表明,硅鉀肥中主要含鉀結(jié)晶相為Ca1.917K0.166SiO_4、K_2MgSiO_4、K_4CaSi_3O_9,非含鉀結(jié)晶相為Ca_2SiO_4、方鎂石(MgO)與新出現(xiàn)的硅酸鈣礦物Ca3Si05,硅鉀肥中鉀主要以結(jié)晶相和非結(jié)晶相兩種形式存在,由此推知,鎂渣與碳酸鉀高溫反應(yīng)的主要機(jī)制是生成了三元體系K_2O-CaO-SiO2與K_2O-MgO-SiO2的混合物。鎂渣類型對硅鉀肥的結(jié)晶及緩釋性能均無明顯影響,冷卻方式、加熱溫度、鎂渣粒徑、保溫時(shí)間、K_20添加量等對硅鉀肥的結(jié)晶性能存在一定影響,進(jìn)而影響了硅鉀肥中硅、鉀的溶出活性；鎂渣中添加2% Fe2O3、1% Al2O3對硅鉀肥的結(jié)晶及緩釋性均無明顯影響,添加3%MgO有利于結(jié)晶相K_2MgSiO_4的生成,可以改善硅鉀肥的硅溶出性與鉀緩釋性。4、通過水中溶出率法和土柱淋溶法,具體考察了硅鉀肥的養(yǎng)分釋放特性,并進(jìn)行了養(yǎng)分釋放動力學(xué)擬合,結(jié)果表明：硅鉀肥破碎的最佳粒度為20～40目,微分溶出率為3.79～3.95%,初期溶出率為23.93～24.62%,與硫酸鉀肥相比具有明顯的緩釋性；硅鉀肥鉀素在檸檬酸中釋放速率明顯高于其在水中的釋放速率,在土壤中的釋放速率明顯低于其在溶液的釋放速率。硅鉀肥在水和2%檸檬酸溶液中的鉀釋放動力學(xué)最優(yōu)模型分別是Elovich模型和一級動力學(xué)模型；水和檸檬酸淋溶,硅鉀肥在土壤中鉀釋放動力學(xué)的最優(yōu)模型分別為雙常數(shù)模型和Elovich模型。硅鉀肥經(jīng)檸檬酸溶出后,晶體結(jié)構(gòu)完全破壞,轉(zhuǎn)變?yōu)榉蔷B(tài)結(jié)構(gòu)；經(jīng)水溶出后,結(jié)晶種類無變化,非晶相明顯增多。硅鉀肥鉀素可根據(jù)作物和土壤需求有效釋放,避免了肥料養(yǎng)分的流失,其養(yǎng)分釋放的本質(zhì)過程是含鉀礦物受溶液作用,結(jié)晶結(jié)構(gòu)破壞,鉀素在溶液中的溶解過程。5、通過硅鉀肥在玉米盆栽試驗(yàn)中的應(yīng)用,考察了硅鉀肥的肥效和農(nóng)業(yè)安全性。結(jié)果表明,施加硅鉀肥可以改善玉米的農(nóng)藝性狀,增加玉米的干物質(zhì)和籽粒產(chǎn)量,顯著提高玉米的吸鉀量、吸硅量,提高玉米的鉀素、硅素利用率；硅鉀肥可不斷彌補(bǔ)土壤因作物吸收而減少的速效鉀,促進(jìn)土壤鉀素的有效化,改善土壤的供硅能力,可滿足玉米整個(gè)生長發(fā)育期的養(yǎng)分需要,且酸性土壤較堿性土壤更有利于硅鉀肥中硅、鉀的有效釋放；硅鉀肥為堿性肥料,施加硅鉀肥使土壤pH值升高,且酸性土壤較堿性土壤更為明顯。硅鉀肥的重金屬含量符合《有機(jī)-無機(jī)復(fù)混肥》國家標(biāo)準(zhǔn),重金屬與氟的浸出濃度遠(yuǎn)低于《危險(xiǎn)廢物鑒別標(biāo)準(zhǔn)-浸出毒性鑒別》標(biāo)準(zhǔn)限值,且達(dá)到地下水Ⅱ類水質(zhì)量標(biāo)準(zhǔn),施加硅鉀肥后,玉米和土壤重金屬含量均在安全范圍,環(huán)境質(zhì)量評價(jià)結(jié)果表明,除水稻土上硅鉀肥處理與硫酸鉀肥處理的內(nèi)梅羅綜合污染指數(shù)(P綜)略大于0.7,屬于警戒外,其余指數(shù)均在安全范圍以內(nèi),施加硅鉀肥不會對作物和土壤環(huán)境安全造成影響。綜上,利用碳酸鉀改性鎂渣制備緩釋性硅鉀肥是可行的,該研究為鎂渣的資源化利用和緩釋肥料制備提供了新思路,對解決鎂渣堆存和肥料流失引發(fā)的環(huán)境問題具有重要意義。
[Abstract]:Magnesium and magnesium alloy is an important strategic material reserves, China is the largest producer and exporter of magnesium. Magnesium smelting mainly adopts pidgeonmagnesiumprocess, each producing 1 tons of metal magnesium, produce 6 to 8 tons of magnesium slag, a large number of magnesium slag discharge accumulation not only occupy the land, but also on the surrounding environment a great impact, magnesium restricts the healthy and sustainable development of the industry. In addition, a serious shortage of potash resources in China, caused serious loss of potassium fertilizer, potassium resource waste and environmental pollution. This research is based on the physicochemical properties and environmental safety of magnesium slag, magnesium slag modified by potassium carbonate, a new type of slow release silicon potash fertilizer the preparation and preparation process of silicon potash crystallization performance, nutrient release characteristics, fertilizer and agricultural safety through theoretical analysis and experimental research of the.1 system, with Pidgeon magnesium slag (MS) as the research object, through XRD, FTIR, TG-DT, SEM-EDS and other characterized points An analysis of the physicochemical characteristics and environmental risk, the results show that the magnesium slag, magnesium slag is alkaline residue a fine powder particles, the particle size to 147 m, the particle size of magnesium slag chemical composition between magnesium slag surface area, apparent density, pore size and similar Portland cement properties, not suitable for adsorption materials, and is suitable for the development of major chemical building materials; magnesium slag is composed of CaO, SiO2, MgO, Fe2O3, Al2O3, the main phase is -Ca_2SiO_4 -Ca_2SiO_4 beta, gamma, MgO and CaO, the secondary component phase is Ca (OH) 2, Mg (OH) 2, CaCO3, MgCO3, mainly in the stable mineral forms, soluble components less; heavy metal content of magnesium slag with organic inorganic compound fertilizer national standards, radionuclides, radiation of internal exposure index and irradiation index reached a national standard of decoration materials (IRa = 1, I = 1.3 y). Heavy magnesium residue Is mainly organic state and residual state stability, leaching concentration of heavy metals and fluorine magnesium residue are far below the limit of hazardous waste standards at home and abroad, even in the most adverse conditions, the effective leaching amount of heavy metals in magnesium slag is still far lower than the minimum toxicity identification value, and the highest content of magnesium slag Cr is mainly in the less toxic Cr3+; Cr, Cu and Ni leaching and leaching agent pH showed a strong correlation, the leaching concentrations were lower than the standard limit of hazardous waste. Therefore, magnesium slag containing soil and crop of beneficial elements, environmental pollution and high safety, low risk, can.2 utilization of agricultural resources, through the single factor experiment and orthogonal experiment, the process of combining the effects of potassium carbonate by modified silicon and potassium magnesium slag system. Firstly, by single factor experiment to determine the effects of factors and levels of orthogonal test; and then to the total activity of silicon in silicon The content of (AST) and the initial dissolution rate of silicon potash fertilizer (Kin) as index, orthogonal test of silicon potassium fertilizer preparation process was optimized. The results show that the influence of each factor on AST and Kin respectively in order of the size of the heating temperature of magnesium slag particle size holding time K_2O content and particle size of magnesium slag heating temperature the holding time of K_20 content, the particle size of magnesium slag and the heating temperature of AST and Kin has the most significant impact (alpha =0.05), to determine the optimal preparation of silicon potassium fertilizer experiment scheme that use air-cooled magnesium slag, K_2O content is 15 ~ 25%, the heating temperature is 1300 degrees centigrade, the holding time of 60min, magnesium slag particle size less than or equal to 80 m, wind cooling system; the silicon potash fertilizer K release rate in line with the national standard < > "part of the slow-release fertilizer slow-release fertilizers, total effective silicon content in silicon magnesium slag is about 2.5 times the yield of potassium was about 90%; Fe2O3 magnesium slag, changing the composition of Al2O3 on properties of silicon potassium fertilizer no obvious Effect of the increase of the content of MgO can improve the performance of.3, silicon and potassium by XRD, the results showed that the crystallization properties of SEM and SEM-EDS, were tested in different conditions for silicon and potassium, silicon and potassium in potassium containing mainly crystalline Ca1.917K0.166SiO_4, K_2MgSiO_4, K_4CaSi_3O_9, non crystalline potassium periclase phase is Ca_2SiO_4 (MgO) with the emergence of new calcium silicate mineral Ca3Si05, potassium silicon potash fertilizer mainly in the crystalline and non crystalline phase two forms exist, accordingly, the main mechanism of magnesium slag and potassium carbonate at high temperature is generated three yuan mixture system of K_2O-CaO-SiO2 and K_2O-MgO-SiO2. There were no obvious effects on the crystallization of magnesium slag type silicon potassium fertilizer and sustained release performance of cooling, heating temperature, magnesium slag particle size, soaking time, crystallization properties of K_20 adding amount of silicon potassium fertilizer has certain effect, thereby affecting the silicon potassium fertilizer of silicon, dissolving active potassium; adding 2% magnesium slag There were no significant effects of Fe2O3,1% Al2O3 on the crystallization of silicon potassium fertilizer and slow-release, adding 3%MgO to produce crystalline K_2MgSiO_4, and potassium release of dissolution of.4 can improve the silicon silicon potash fertilizer, the water dissolution rate method and soil column leaching method, and analyzes the silicon potash fertilizer nutrient release characteristics, and the nutrient release kinetics, the results show that the optimum size of silicon potassium fertilizer is 20 ~ 40 mesh broken, differential dissolution rate is 3.79 ~ 3.95%, the initial dissolution rate ranged from 23.93 to 24.62%, compared with the sulfuric acid potassium fertilizer has obvious controlled release; silicon potassium potassium in the citric acid release rate was significantly higher than that in the the release rate of water, the release rate in soil was significantly lower than that in solution. The release rate of silicon and potassium in water and 2% citric acid solution of potassium release kinetics of optimal models are the Elovich model and the first-order kinetic model; water and lime Citric acid leaching, the optimal model of release kinetics of silicon and potassium in soil potassium were double constant model and Elovich model. The silicon potassium fertilizer by citric acid dissolution, crystal structure completely destroyed, transformed into amorphous structure; by water dissolution, crystallization type change, amorphous silicon and potassium potassium are increased obviously. According to the demand of crop and soil elements can effectively release, to avoid the loss of nutrients, the nature of the nutrient release is affected by potassium mineral solution, crystal structure damage, the dissolution process of potassium.5 in solution, the application experience in maize pot through silicon potash fertilizer, K fertilizer and silicon were investigated agricultural safety. The results showed that the agronomic traits of maize applied silicon potash fertilizer can improve and increase maize dry matter and grain yield, K significantly increased the amount of corn, Si uptake by maize, improve the utilization rate of potassium, silicon; silicon potassium fertilizer can not Break up the potassium for crop absorption decreased, promote soil effective potassium, improve the silicon supplying capacity of the soil, the whole growth period of corn can meet the nutrient requirements, and more acidic soil alkaline soil is more conducive to the effective release of silicon and potassium silicon, potassium; silicon potassium alkaline fertilizer, applying silicon fertilizer the soil pH value increased, and the soil is acidic alkaline soil is more obvious. The heavy metal content of silicon potassium fertilizer with < semiorganic fertilizer > national standard, the leaching concentration of heavy metals and fluorine is far lower than the identification standard for hazardous wastes - > > standard leaching toxicity identification limits, and reached the groundwater class II water quality standards. Application of silicon potassium fertilizer, heavy metal content in corn and soil in the safe range, environmental quality evaluation results show that in addition to paddy soil silicon potash fertilizer treatment and potassium sulfate fertilizer treatment Nemero comprehensive pollution index (P ensemble) is slightly greater than 0 .7, which belongs to the warning, the rest of the index in the safe range, application of silicon potassium fertilizer will not affect crop and soil environmental safety. In summary, the use of potassium carbonate prepared slow-release silicon modified potassium magnesium slag system is feasible, the study for the resource utilization of magnesium slag and fertilizer preparation provides a new idea that is of great significance to solve the environmental problem of magnesium slag piling and fertilizer loss caused.

【學(xué)位授予單位】：山西大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2016
【分類號】：TQ443

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 李詠玲;戈甜;程芳琴;;不同處理方式對鎂渣理化特性的影響[J];無機(jī)鹽工業(yè);2016年03期

2 張耀君;康樂;劉禮才;;一種用于光催化染料降解的新型鎂渣基納米復(fù)合膠凝材料（英文）[J];稀有金屬材料與工程;2015年12期

3 李詠玲;梁鵬翔;范遠(yuǎn);程芳琴;;鎂渣的資源利用特性與重金屬污染風(fēng)險(xiǎn)[J];環(huán)境化學(xué);2015年11期

4 梁一然;李明照;梁曉波;王國衛(wèi);張耀斌;毛嘉;任川兮;馮小琴;;鹽酸酸浸鎂還原渣提高有效硅含量[J];有色金屬(冶煉部分);2015年07期

5 陳玉潔;韓鳳蘭;羅釗;;鎂渣固化/穩(wěn)定污酸渣中重金屬銅和鎘[J];無機(jī)鹽工業(yè);2015年07期

6 樊保國;段麗萍;姬克丹;侯宇;喬曉磊;金燕;;鎂渣脫硫劑孔隙結(jié)構(gòu)分形特性的研究[J];工程熱物理學(xué)報(bào);2015年03期

7 邱潤強(qiáng);許征鵬;;高爐爐渣微水淬法余熱回收技術(shù)開發(fā)[J];山東冶金;2014年01期

8 張晶;石揚(yáng)娟;任潔;劉周;石英堯;;硅肥用量對水稻莖稈抗折力的影響研究[J];中國農(nóng)學(xué)通報(bào);2014年03期

9 葛少彬;劉敏;蔡昆爭;蔡一霞;駱世明;;硅介導(dǎo)稻瘟病抗性的生理機(jī)理[J];中國農(nóng)業(yè)科學(xué);2014年02期

10 樊保國;楊靖;劉軍娥;金燕;;鎂渣脫硫劑的水合及添加劑改性研究[J];熱能動力工程;2013年04期

相關(guān)重要報(bào)紙文章 前1條

1 鮑榮華;徐曙光;姜雅;;產(chǎn)能持續(xù)增長 貿(mào)易量已達(dá)高峰[N];中國國土資源報(bào);2015年

相關(guān)博士學(xué)位論文 前1條

1 鄒洪濤;環(huán)境友好型包膜緩釋肥料研制及其養(yǎng)分控釋機(jī)理的研究[D];沈陽農(nóng)業(yè)大學(xué);2007年

，

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